taxonID	type	description	language	source
006F87D3FFE6EC1CB594FE13FAD4D283.taxon	materials_examined	Materials examined. [Vietnam] 2 ♂, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, Q. T. Phan leg. (PQTC); 1 ♂, Thua Thien-Hue Prov., 21. VI. 2016, T. Kompier leg. (TKC); 1 ♀, Hon Ba Nature Reserve (1,400 m), Nha Trang City, Khanh Hoa Prov., 23. VI. 2008, H. Karube leg. (KPM); 7 ♂, Bao Lam, Bao Loc District, Lam Dong Prov., 29. IV. 2015, H. Karube leg. (PQTC); 1 ♂, Tr’hy, Tay Giang District, Quang Nam Prov., 18. V. 2017, Q. T. Phan leg. (PQTC); 2 ♂, Bach Ma National Park, Thua Thien-Hue Prov., 28. VI. 2017, Q. T. Phan leg. (PQTC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE6EC1CB594FE13FAD4D283.taxon	description	Female specimen used for description: 1 ♀, Hon Ba Nature Reserve, 23. VI. 2008, H. Karube leg.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE6EC1CB594FE13FAD4D283.taxon	materials_examined	Other materials confirmed by field observations. [Vietnam] 1 ♂, Quang Tri Prov., 22. VI. 2016, T. Kompier; Some individuals, Bach Ma, Thua Thien-Hue Prov., 5 – 8. VIII. 2016, T. Kompier. Notes. This species differs from all described Anisopleura species by the presence of two long processes on the posterior lobe of prothorax, both in male (Fig. 1 a) and female (Fig. 1 d, f, g). The female is described here for the first time.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE6EC1CB594FE13FAD4D283.taxon	description	Description of female. Posterior lobe of prothorax with two processes as in the male (Fig. 1 d, f, g). The color pattern of head, thorax and legs is as in the male (Fig. 1 d, e), apart from the antehumeral stripe, the anterior end of which has an oval shape with a dark core and which tapers off earlier towards the posterior end of mesepisternum (Fig. 1 d). Wings (Fig. 1 h) are hyaline with black venation. The number of Ax is 18 – 19 in both wings. Abdomen (Fig. 1 d) is black with pale yellowish lateral markings on abdominal segments as follows: S 1 – 2 have a large oblong marking; S 3 – 7 have an oval anterior marking, and a thin stripe running along the lateral suture, becoming thinner towards their posterior ends; S 8 is black with a small oval spot near posterior margin; and S 9 – 10 are wholly black. Ovipositor black, thick and robust as in Fig. 1 d. Measurement (in mm). HW 32; abdomen (incl. appendages) 29.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE6EC1CB594FE13FAD4D283.taxon	distribution	Distribution. Vietnam (Thua Thien-Hue, Quang Nam, Quang Tri, Lam Dong and Khanh Hoa Provinces).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE1EC1DB594FDC0FC32D0D2.taxon	materials_examined	Materials examined. [Vietnam] 2 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 18. V. 2015, Q. T. Phan and F. Hayashi leg. (PQTC); 1 ♂, Pia Oac Nature Reserve, Cao Bang Prov., 18. VI. 2015, T. Kompier leg. (TKC); 1 ♂, Mau Son, Lang Son Prov., 28. VI. 2014, T. Kompier leg. (TKC); 1 ♂, Mau Son, Lang Son Prov., 7. VI. 2014, T. Kompier leg. (TKC); 1 ♂, Khau Pha, Tu Le, Yen Bai Prov., 19. V. 2014, and 1 ♂, Khau Pha, Tu Le, Yen Bai Prov., 16. IX. 2015, Q. T. Phan leg. (PQTC); 1 ♂, Tu Le, Yen Bai Prov., 11. VII. 2015, T. Kompier leg. (TKC); 1 ♂, Tu Le, Yen Bai Prov., 1. VI. 2014, T. Kompier leg. (TKC); 1 ♂, Nam Bung, Yen Bai Prov., 26. IV. 2015, T. Kompier leg. (TKC); 1 ♂, Phu Tho Prov., 23. XI. 2014, T. Kompier leg. (TKC); 1 ♂, Phu Tho Prov., 20. XI. 2016, T. Kompier leg. (TKC); 2 ♂, Tr’hy, Tay Giang District, Quang Nam Prov., 15. V. 2012, Q. T. Phan leg. (PQTC); 1 ♂ 1 ♀, Bach Ma National Park, Thua Thien-Hue Prov., 28. VI. 2017, Q. T. Phan leg. (PQTC); [China] 1 ♀, Nanling, Guangdong Prov., 2005, M. Takakuwa leg. (KMP). Other materials confirmed by field observations. [Vietnam] 1 ♂, Lao Cai Prov., 25. V. 2015, T. Kompier; Some individuals, Cao Bang Prov., VI, VII 2014, V, VI, IX 2015, T. Kompier; Some individuals, Lang Son Prov., VI. 2014, V, VII 2015, T. Kompier; Some individuals, Yen Bai Prov., V, VI, VII, IX 2014, IV, V, VI, VII 2015, VII 2016, T. Kompier; Some individuals, Bach Ma, Thua Thien-Hue Prov., 5 – 8. VIII. 2016, T. Kompier. Notes. This is a common species in high mountain areas of Vietnam. Male and female resemble each other in body color pattern (Fig. 2 a – b, e – f). Paraprocts are very short in lateral view, cerci are generally axe-shaped, with their blades directed inward and with a small knob along their inner margin, and furnished by a robust hook-shaped latero-apical tooth, so that they look bifid in lateral view (Fig. 2 c – d). This species is closely related to Anisopleura pelecyphora Zhang, Hämäläinen & Cai, 2014 from Yunnan, southern China. According to the original description, Anisopleura pelecyphora is separated from A. qingyuanensis by its completely hyaline wings, which are distinctly yellow tinted basally in A. qingyuanensis. Cerci of Anisopleura pelecyphora are broader and their margin is more strongly curved than in A. qingyuanensis.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE1EC1DB594FDC0FC32D0D2.taxon	distribution	Distribution. Vietnam (Lao Cai, Cao Bang, Lang Son, Vinh Phuc [Do & Dang 2007, Hämäläinen & Karube 2013], Yen Bai, Phu Tho, Thua Thien-Hue and Quang Nam Provinces), Laos (Xiangkhouang Province) (Hämäläinen & Karube 2013; Yokoi & Souphanthong 2014), China (Zhejiang, Jiangxi, Hunan, Guizhou, Guangdong and Guangxi Provinces) (Hämäläinen & Karube 2013).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE0EC1DB594FC70FD9FD4B5.taxon	materials_examined	Materials examined. [Vietnam] 3 ♀, Sapa, Lao Cai Prov., 1500 – 2000 m, native collectors (KPM); 1 ♀, Tu Le, Yen Bai Prov., 1. VI. 2014, T. Kompier leg. (TKC); 1 ♀, Yen Bai Prov., 11. VII. 2016, T. Kompier (TKC); 2 ♂, Gari, Tay Giang District, Quang Nam Prov., 11. X. 2017, To Van Quang leg. (PQTC). [China] 1 ♂, Dali city, Yunnan Prov., China, 18. VI. 2013, Z. Haomiao leg. (KPM). Other materials confirmed by field observations. [Vietnam] 5 exs, Yen Bai Prov., 10. V. 2014, T. Kompier; 1 ♂, Yen Bai Prov., 7. IX. 2014, T. Kompier; 4 exs, Lai Chau Prov, 28 – 29. V. 2017, T. Kompier. Notes. This is the first formal record of this species from Vietnam (but see below). Anisopleura yunnanensis resembles A. subplatystyla from India, Sikkim and Thailand by the U-shaped or complete loop on the mesepisternum of both male and female (Fig. 3 a, d). Cerci are long and tapering in lateral view (Fig. 3 b – c). Hämäläinen & Karube (2013) already recorded the occurrence of Vietnamese specimens (from Sapa) belonging to either Anisopleura yunnanensis or A. subplatystyla, but left their specific identity open, and urged the need of further study to confirm whether these taxa really represent two distinct species. Because the known distribution areas of Vietnamese populations are close to the distribution area of Anisopleura yunnanensis (Yunnan and Guangxi Provinces in southern China), we tentatively treat the Vietnamese populations as A. yunnanensis. To confirm identification of Vietnamese populations, molecular analysis is needed of populations of Anisopleura yunnanensis and A. subplatystyla from Vietnam, China, Thailand and India. It is noteworthy that a population of Anisopleura sp. occurs on Pia Oac Nature Reserve, Cao Bang Province that is structurally identical to A. yunnanensis / A. subplatystyla, but has a thick, straight and decidedly bluish antehumeral stripe. Pending further molecular studies, we refrain from a specific identification of this population.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE0EC1DB594FC70FD9FD4B5.taxon	distribution	Distribution. Vietnam (Lai Chau, Lao Cai, Yen Bai and Quang Nam Provinces), China (Yunnan and Guangxi Provinces) (Wilson & Reels 2003).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE3EC1FB594F946FA99D14F.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂ 1 ♀, Xuan Son National Park, Phu Tho Prov., 30. V. 2015, T. Kompier leg. (TKC); 1 ♂, Tam Dao National Park, Vinh Phuc Prov., 18. V. 2014, T. Kompier leg. (TKC). [China] 1 ♀, Zhizhiqu, Zhuangzu, Guangxi Prov., 2 – 4. VI. 2004, H. Karube leg. (KPM); 1 ♀, Nanling, Guandong Prov., 22 – 26. VII. 2004, Y. Kishida leg. (KPM); 1 ♀, Nanling, Guandong Prov., 30. VI. 2010, Z. Haomiao leg. (KPM); 5 ♂ 5 ♀, Damingshan, Guangxi Prov., 6 – 7. VI. 2014, F. Hayashi leg. (FHC). Notes. Male Bayadera bidentata is characterized by an entirely blackish thorax and abdomen (Fig. 4 a), the lower half of the thorax extensively covered with grey pruinosity in life. Wings are hyaline, very faintly tinged yellow from the base to the level of pterostigma (Fig. 4 e). Cerci have large spines and two prominent tubercles on inner sides (Fig. 4 b – d). Yellow markings of the female thorax vary from the relatively poorly marked type in Guangdong Province, China (Fig. 4 f), to the more extensively marked types in Guangxi Province, China and northern Vietnam (Fig. 4 g). The tip of female abdomen has one distinct oval spot laterodorsally on S 9 (Fig. 4 h).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE3EC1FB594F946FA99D14F.taxon	distribution	Distribution. Vietnam (Cao Bang [Do & Dang 2007], Phu Tho and Vinh Phuc Provinces), China (Zhejiang, Fujian, Guangdong, Hubei, Guangxi and Sichuan Provinces) (Wilson & Reels 2003, Hämäläinen 2004).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE2EC11B594F889FAACD3A2.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Pia Oac Nature Reserve, Cao Bang Prov., 22 – 24. V. 2010, H. Karube leg. (KPM); 2 ♂ 2 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 16 – 20. V. 2015, Q. T. Phan and T. Kompier leg. (PQTC); 2 ♂, Pia Oac Nature Reserve, Cao Bang Prov., 1. V. 2015, T. Kompier leg. (TKC); 2 ♂ 1 ♀, Dong Van, Ha Giang Prov., 2. V. 2011, F. Hayashi leg. (FHC); 1 ♂, Tam Dao National Park, Vinh Phuc Prov., 24. IV. 2016, T. Kompier leg. (TKC). [China] ♂ holotype, 1. V. 1946, and ♀ allotype, 6. V. 1946, Kuatun, Fukien, Asahina’s leg. (NSMT); 1 ♂, Shaoguan, Nanling Reserve, Guangdong Prov., 21. V. 2009 and 2 ♂, same location, 9. VI. 2011, H. Zhang leg. (KPM); 1 ♂ 1 ♀, Cenwanglaoshan, Guangxi Prov., 18. V. 2016, F. Hayashi leg. (FHC). Other materials confirmed by field observations. [Vietnam] 3 ♂, Tam Dao, Vinh Phuc Prov., 8. V. 2016, T. Kompier; 2 exs, Tam Dao, Vinh Phuc Prov., 1. V. 2017, T. Kompier. Notes. This species is recorded from Vietnam for the first time. The specimens from Dong Van match the original description (Asahina 1973) well, especially by having the heart-shaped yellow marking straddling the metepisternum and metepimeron of synthorax (Fig. 5 a, d). Hämäläinen (2004) upgraded Bayadera continentalis from subspecies to species level, because there are clear differences in the colour pattern and structure of anal appendages. In Bayadera continentalis paraprocts are only narrowly separated in dorsal view, while those of B. brevicauda are more widely spaced. However, males from Pia Oac Nature Reserve of northern Vietnam and from Guangdong Prov. of southern China differed slightly from the type specimens of Bayadera continentalis by having a very dark synthorax with the marking on metepisternum reduced into a narrow stripe (Fig. 5 e); paraprocts of the specimens from Dong Van (Vietnam) and Guangxi (China) are more closely spaced as in the original description (Fig. 5 b – c) although the paraprocts of the specimens from Pia Oac are separated further, but the deep incision of S 10 and the shape of the cerci with strongly curved apex supports identification as B. continentalis (Fig. 5 f). In the specimens of Dong Van and Guangdong, labrum, mandibles, genae, and color of the dorsal head markings are yellowish, but bluish in the males from Pia Oac Mountain. Wings of the specimens from Guangdong and Dong Van are hyaline, but slightly darkened at tip in males from Pia Oac (Fig. 5 h).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE2EC11B594F889FAACD3A2.taxon	distribution	Distribution. Vietnam (Ha Giang, Cao Bang and Vinh Phuc Provinces), China (Zhejiang, Fujian, Hunan, Guangdong and Guangxi Provinces) (Wilson & Reels 2003, Hämäläinen 2004, Wilson & Zaifu 2007).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFECEC11B594FEA0FC69D4D7.taxon	materials_examined	Materials examined. [Vietnam] 2 ♂, Ha Giang Prov., 1. VII. 2014, T. Kompier (TKC); 1 ♂ 1 ♀, Thanh Cong, Nguyen Binh, Cao Bang Prov., 17. V. 2015, Q. T. Phan and F. Hayashi leg. (PQTC); 1 ♂, Tu Le, Mu Cang Chai, Yen Bai Prov., 19. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂, Nam Bung, Yen Bai Prov., 11. V. 2014, T. Kompier leg. (TKC). Other materials confirmed by field observations. [Vietnam] 15 exs, Cao Bang Prov., 18. VI. 2015, T. Kompier; 1 ♂, Cao Bang Prov., 27. VI. 2015, T. Kompier; Some individuals, Yen Bai Prov., V, VI, VII. 2014, VI, VII. 2015, VII. 2016, VII. 2017, T. Kompier. Notes. Bayadera hatvan resembles B. indica (Selys, 1853). In both species the tip of cerci is dilated in the form of a triangle, the inner sides have a robust spine near the base and two tubercles besides the robust spines (Fig. 6 b – c). Wings (Fig. 6 d) are hyaline, but darkened at the tip. Female resembles the male in thoracic marking; posterior lobe of prothorax has two short processes (Fig. 6 e). Hämäläinen & Kompier (2015) presumed that specimens from Yunnan, southern China, identified by Davies & Yang (1996: p. 152, Figs 26 – 28) as Bayadera indica are likely to be B. hatvan rather than B. indica. A re-evaluation of Chinese specimens should resolve this matter.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFECEC11B594FEA0FC69D4D7.taxon	distribution	Distribution. Vietnam (Ha Giang, Cao Bang and Yen Bai Provinces).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEFEC13B594FF10FE94D6B6.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Tu Le, Yen Bai Prov., 25. V. 2015, T. Kompier leg. (TKC); 1 ♂ 1 ♀, Tu Le, Yen Bai Prov., 30. VI. 2015, T. Kompier leg. (TKC); 1 ♂, Tu Le, Yen Bai Prov., 11. V. 2014, T. Kompier leg. (TKC); 1 ♂, Tu Le, Yen Bai Prov., 11. VII. 2015, T. Kompier leg. (TKC); 1 ♂, Tu Le, Yen Bai Prov., 16. IX. 2015, Q. T. Phan leg. (PQTC); 1 ♂, Lai Chau Prov., 17. IV. 2014, T. Kompier leg. (TKC); 1 ♂, Hoang Lien Son, Lao Cai Prov., 23. VI. 2015, T. Kompier leg. (TKC); 1 ♂, Lai Chau Prov., 28. V. 2017, T. Kompier leg. (TKC); 3 ♂, Ch'Om, Tay Giang District, Quang Nam Prov., 18. IX. 2016, V. Q. To leg. (PQTC). [China] 1 ♂ 1 ♀, Yangbijiang River, Yangbi County, Dali, Yunnan Prov., 12. VI. 2013, H. Zhang leg. (KMP); 1 ♂, Xiangzhigou, Xinpuxiang Village, Guiyang City, Guizhou Prov., 28. VIII. 2012, H. Zhang leg. (KMP). [Laos] 3 ♂, N. Sekong, 5. VII. 2011, T. Miyashita leg. (KPM). Other materials confirmed by field observations. [Vietnam] Some individuals, Hoang Lien Son, Lao Cai Prov., VII 2014, VI 2015, T. Kompier; Some individuals, Yen Bai Prov,. VI. 2014, VI, VII, VIII, X 2015, VII 2016, T. Kompier; 6 exs, Cao Bang Prov., 18. VI. 2015, T. Kompier; Some individuals, Bach Ma, Thua Thien-Hue Prov., 5 – 8. VIII. 2016, T. Kompier. Notes. This species, preliminarily identified as Bayadera hyalina, is recorded from Vietnam and Laos for the first time. The identification of published or unpublished ‘ Bayadera hyalina ’ material collected outside the type locality of hyalina (Khasia Hills, Meghalaya, India), such as those from Thailand, Laos, Vietnam and China (Yunnan and Guizhou), remains uncertain until the material can be directly compared with topotypical Indian material. Selys (1879) described Bayadera hyalina based on a single incomplete male from ‘ Khasia Hills, Assam’ (in the present Meghalaya State, India); this holotype lacks abdominal segments S 7 – 10 including appendages. Later, Fraser (1928, 1934) redescribed males and females based on several specimens from its type locality and noted and illustrated that the cerci have large spines near the base, but lack tubercles. However, Lahiri (1987) reported “ presence of a small but prominent median tubercle on inner surface of superior anal appendages ” in the specimens from Shillong, close to the type locality. Confusingly the position of the interior spine in cerci differs considerably in the rather crude illustrations presented by Fraser and Lahiri. The materials from Vietnam, Laos and China (Guizhou) used in this study have these characteristics and we identified these materials all as Bayadera hyalina, although we could not examine the holotype or materials from the type locality. A similar species, Bayadera strigata Davies & Yang, 1996, was described from Dali, Yunnan, southern China. Although we could not examine the type specimens of this species, we examined a pair of specimens obtained from its type locality, Dali, Yunnan. The structure of anal appendages of these specimens considered to be Bayadera strigata resembles that of B. hyalina from Vietnam, Laos, and China (Guizhou) with cerci having robust spines near the base, and 1 – 2 small tubercles in addition. Thoracic pattern of the supposed Bayadera hyalina (sensu lato; including B. strigata) varies geographically. Male prothorax is entirely black in central Vietnam, Laos and China (Guizhou), excluding two tiny spots on the margin of the posterior lobe of Chinese specimens, but prothorax has two yellow spots on the median lobes in northern Vietnam (Fig. 7 a, f) and is even more prominently marked in Yunnan (China) (Fig. 7 g – h). Laotian specimens lack humeral stripe on male synthorax. This stripe is reduced to two oval spots at anterior margin of male synthorax in Guizhou (China), and well defined as humeral stripes in northern Vietnam and Yunnan (China) (Fig. 7 a, f – h). Cerci of Laotian and Chinese specimens have two small tubercles besides the basal large spine, but those of Vietnamese specimens have only one typical tubercle (Fig. 7 b – d). Thoracic pattern of the female from Yunnan (China) is well defined with robust stripes (Fig. 7 h), but it less clearly defined with only narrow stripes in the female from Vietnam (Fig. 7 f). Wings of all specimens are hyaline, excluding two males from Yen Bai Province and many males from Guizhou, China, that have distinct apical darkening from the apical end of pterostigma to the wing border as shown in Figure 7 e. Donnelly (1994) recorded four males of Bayadera (cf. hyalina) from Doi Inthanon, Chiang Mai, Thailand, with a brief note that " this species is not longicauda, […,] the appendages have the superior with the sharp ventral basal spine and curvature resembling Fraser’s figure ". Later, Hämäläinen & Pinratana (1999) and Hämäläinen (2017) identified the Thai specimens as Bayadera hyalina.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEFEC13B594FF10FE94D6B6.taxon	distribution	Distribution. Vietnam (Lai Chau, Lao Cai, Yen Bai, Cao Bang, Quang Nam, Thua Thien-Hue and Lam Dong [Hämäläinen in litt.] Provinces), China (Yunnan and Guizhou Provinces), Laos (Sekong Province), Thailand (Chiang Mai and Loei Provinces) (Hämäläinen 2017), India (Meghalaya and West Bengal States) (Fraser 1934, Lahiri 1987).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEEEC14B594F993FF5FD42D.taxon	materials_examined	Materials examined. [Vietnam] 3 ♂ 4 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 21 – 26. V. 1998, H. Karube leg. (PKM); 1 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 31. V. 2015, T. Kompier leg. (TKC); 1 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 15. V. 2015, F. Hayashi leg. (FHC); 1 ♂ 1 ♀, Deo Tram Ton, Sapa, Lao Cai Prov., 21. VI. 2002, H. Karube leg. (PKM); 1 ♂, Sa Pa, Lao Cai Prov, 25. V. 2015, T. Kompier leg. (TKC). [China] 1 ♂, Bikou (867 m), Gansu Prov., 9. VII. 2005, X. Yu leg. (PQTC); 1 ♀, Emei, Sichuan Prov., 5. VII. 2011, F. Hayashi leg. (FHC); 2 ♂ 2 ♀, Tiamushan, Zhejiang Prov., 8. VIII. 2007, X. Yu leg. (PQTC); 3 ♂ 1 ♀, Fengyangshan, Lishui, Zhejiang Prov., 28. VII. 2007, X. Yu leg. (PQTC); 2 ♂ 2 ♀, Wuyangling, Taishun, Zhejiang Prov., 2. VIII. 2005, K. Yunling leg. (PQTC); 2 ♀, Nanling, Guangdong Prov., 22 – 26. VII. 2004, H. Karube leg. (KPM); 2 ♂ 2 ♀, Qingliangfeng, Linan, Zhejiang Prov., 13. VIII. 2007, X. Yu leg. (PQTC); 1 ♂, Lujianhe Stream, Zigui County, Hubei Prov., 4. VIII. 2012, H. Zhang leg. (KMP). Other materials confirmed by field observations. [Vietnam] Some individuals, Pia Oac, Cao Bang Prov., V, VI. 2015, T. Kompier; Some individuals, Lao Cai Prov., V, VI, VIII. 2015, V. 2 0 16, T. Kompier; Some individuals, Tam Dao, Vinh Phuc Prov., VI, VII. 2016, T. Kompier. Notes. Bayadera melanopteryx differs from all described Bayadera species by the extensively darkened wingtips of both male and female. The dark area varies from covering the wings almost completely to only covering the apical quarter, as pointed out by Hämäläinen (2004). In Vietnam all specimens examined had the apical quarter of their wings dark brown (males) or brown (females) (Fig. 8 g). Synthorax of male B. melanopteryx has clearly defined yellowish stripes when young (Fig. 8 f), but these stripes become obscured or disappear entirely with age (Fig. 8 a). Anal appendages are similar to those of Bayadera hyalina and B. bidentata in having cerci with a robust spine at the base (Fig. 8 b – d). Female Bayadera melanopteryx is characterized by largely pale metepimeron (Fig. 8 e).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEEEC14B594F993FF5FD42D.taxon	distribution	Distribution. Vietnam (Cao Bang, Lao Cai and Vinh Phuc Provinces), China (Gansu, Shaanxi, Hubei, Sichuan, Zhejiang, Fujian, Guangdong and Guangxi Provinces) (Hämäläinen 2004, Wilson & Reels 2003, Zhang 2010).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC15B594FF10FA38D078.taxon	materials_examined	Materials examined. [Vietnam] 7 ♂ 2 ♀, Sa Pa, Lao Cai Prov., 22. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂ 1 ♀, Sa Pa, Lao Cai Prov., 25. V. 2015, T. Kompier leg. (PQTC); 1 ♂ 1 ♀, Sa Pa, Lao Cai Prov., 18. V. 2015, T. Kompier leg. (TKC); 1 ♂, Sa Pa, Lao Cai Prov., 28. V. 2016, T. Kompier leg. (TKC). [China] 3 ♂, Emeishan, 800 m, Sichuan Prov., 25. VII. 2017, X. Liu leg. (FHC). Other materials confirmed by field observations. [Vietnam] 17 exs, Lai Chau Prov., 28 – 29. V. 2017, T. Kompier. Notes. This is a new record for Vietnam. Male Bayadera nephelopennis is characterized by a black body with pruinosity on legs, basal abdomen, and ventral sides of synthorax (Fig. 9 a). Wings are cloudy light brown in basal two-thirds with hyaline apex in Chinese males, but hyaline with slightly darkened apex in Vietnamese ones (Fig. 9 e). Anal appendages are long in lateral view and cerci are characterized by two well defined closely spaced tubercles (Fig. 9 b – d). Female is separated from other Bayadera species by a broad dorsal stripe over mesepisternum of synthorax (Fig. 9 f).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC15B594FF10FA38D078.taxon	distribution	Distribution. Vietnam (Lao Cai and Lai Chau Provinces), China (Sichuan Province) (Davies & Yang 1996).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC17B594F8B3FE49D116.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Pia Oac Nature Reserve, Cao Bang Prov., 30. VII. 2014, T. Kompier leg. (TKC); 2 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 18 – 27. VI. 2015 (TKC); 2 ♂, Pia Oac Nature Reserve, Cao Bang Prov., 23. V. 2015 (TKC); 7 ♂ 1 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 19. V. 2015, Q. T. Phan leg. (PQTC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC17B594F8B3FE49D116.taxon	description	Female specimen used for description: 1 ♀, Pia Oac Nature Reserve, Cao Bang Prov., 18 – 27. VI. 2015, T. Kompier leg.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC17B594F8B3FE49D116.taxon	materials_examined	Other materials confirmed by field observations. [Vietnam] Some individuals, Cao Bang Prov., V, VI. 2015, VI. 2016, T. Kompier; Some individuals, Yen Bai Prov., VI. 2015, VII. 2016, T. Kompier; 1 ♀, Xuan Son National Park, Phu Tho Prov., 29. VI. 2015, T. Kompier; 1 ♀, Yen Bai Prov., 10. VII. 2017, T. Kompier. Notes. Bayadera serrata was described by Davies & Yang (1996) on the basis of a single mature male, collected in Dali, Yunnan, and recently recorded in northern Vietnam and northern Thailand (Hämäläinen 2013, 2017). This species resembles Bayadera kinnara Hämäläinen, 2013 from Myanmar. Both species are characterized by their complex anal appendages with strongly downward curving cerci bearing a large dorsal spine (Fig. 10 c – e). The female of Bayadera serrata is described here for the first time.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC17B594F8B3FE49D116.taxon	description	Description of female. Body color pattern of the female superficially resembles the male. In the head (Fig. 10 f – g), labrum and bases of mandibles are yellow, excluding a black band at anterior margin mandible base. Anteclypeus is entirely black (but yellowish in the male). Postclypeus is yellow, excluding black anterior margin. Genae yellow, which extends upward along margin of compound eyes and inward across the antefrons, but not connecting over the postclypeus as in the male. (Fig. 10 b). The first segment of antennae is black with an oval yellow spot, and second and third segments are entirely black. Ocelli are amber with two small yellow spots positioned between lateral ocelli and central ocellus. Occipital ridge is black, without the two oval spots of the male (Fig. 10 a – b). The blackish prothorax has two large yellow markings on the median lobe. Synthorax is black with yellow stripes similar to the male, but the stripes over mesepisternum and metepimeron form an S-shape (Fig. 10 a). Legs are black with yellow stripes internally. Wings are hyaline with black venation (Fig. 10 i). Abdomen is black with yellow stripes as follows: S 1 with a small lateral marking; S 2 – 7 with a lateral stripe which is broad at anterior margin but quickly narrows and tapers off posteriorly; S 8 with a large posterolateral spot and S 9 with a large dorsolateral spot; S 10 with a semicircular lateral marking (Fig. 10 h). Ovipositor structure as in Figure 10 h. Measurement (in mm). HW 40 – 41; abdomen (incl. appendages) 40 – 41.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFE8EC17B594F8B3FE49D116.taxon	distribution	Distribution. Vietnam (Cao Bang, Yen Bai and Phu Tho Provinces), China (Yunnan Province) (Davies & Yang 1996), Laos (Vientiane Province) (Yokoi & Souphanthong 2014), Thailand (Chiang Mai and Phetchabun Provinces) (Hämäläinen 2017).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEAEC09B594FC6BFE57D2FE.taxon	materials_examined	Materials examined. [Vietnam] 2 ♂, Mau Son Mt., Loc Binh District, Lang Son Prov., 25. IV. 2012, Q. T. Phan leg. (PQTC); 2 ♂ 2 ♀, Xuan Son National Park, Phu Tho Prov., 15. IX. 2015, Q. T. Phan leg. (PQTC); 1 ♂, Cuc Phuong National Park, Ninh Binh Prov., 27. V. 1993, H. Karube leg. (PKM); 1 ♂, unknown province, 1994, H. Karube leg. (PKM); 1 ♂, Xuan Son National Park, Phu Tho Prov., 20. X. 2013, T. Kompier leg. (TKC); 2 ♀, Tam Dao National Park, Vinh Phuc Prov., 16. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂, Tam Dao National Park, Vinh Phuc Prov., 7. VIII. 2013, T. Kompier leg. (TKC); 1 ♂, Quang Binh Prov., 23. VI. 2016, T. Kompier leg. (TKC); 1 ♂, Quang Tri Prov., 5. V. 2016, T. Kompier leg. (TKC); 3 ♂ 1 ♀, Ba Na Nature Reserve, Da Nang City, 25. V. 2015, Q. T. Phan leg. (PQTC); 4 ♂, Kon Ka Kinh National Park, Gia Lai Prov., 23. IV. 2013, Q. T. Phan leg. (PQTC); 1 ♀, Chu Mom Ray National Park, Kon Tum Prov., 24. V. 2017, Q. T. Phan leg. (PQTC); 7 ♂ 5 ♀, Bach Ma National Park, Thua Thien- Hue Prov., 28. VI. 2017, Q. T. Phan leg. (PQTC); [China] 1 ♀, Damingshan, Guangxi Prov., 6. VI. 2014, F. Hayashi leg. (FHC); [Laos] 1 ♀, Xam Neua, Houaphan Prov., 8. VI. 2017, X. Liu leg. (FHC). Other materials confirmed by field observations. [Vietnam] Some individuals, Pia Oac, Cao Bang Prov., V, VI. 2015, VI. 2016, T. Kompier; Some individuals, Mau Son, Lang Son Prov., 28. VI. 2014, T. Kompier; Some individuals, Xuan Son National Park, Phu Tho Prov., V, VI, VII, IX, X. 2014, V, VI, VIII, IX, X. 2 0 15, VII, VIII. 2016, T. Kompier; 3 exs, Hoa Binh Prov., 27. VI. 2014, T. Kompier; Some individuals, Tam Dao National Park, Vinh Phuc Prov., VIII. 2013, V. 2014, VI, VII. 2016, T. Kompier; Some individuals, Ba Vi National Park, Ha Noi, V, VII, IX. 2013, V. 2014, T. Kompier; Some individuals, Cuc Phuong National Park, Ninh Binh Prov., VI. 2015, VII. 2016, T. Kompier; Some individuals, Thanh Hoa Prov., V, VII. 2015, T. Kompier; Some individuals, Quang Binh Prov., V, VI. 2016, T. Kompier; Some individuals, Quang Tri Prov., V, VI. 2016, T. Kompier; Some individuals, Bach Ma, Thua Thien-Hue Prov., 5 – 8. VIII. 2016, T. Kompier; 1 ♀, 9. VII. 2017, Bac Kan Prov., T. Kompier. Notes. This species was originally described from central Vietnam as Bayadera vietnamensis (van Tol & Rozendaal 1995). Later, it was transferred to the genus Schmidtiphaea by Wilson & Reels (2003) based on the specimens from Guangxi, southern China. Hämäläinen (2003) erected the new genus Cryptophaea and moved vietnamensis into it. This species is a medium-sized damselfly with small and slender thorax, hyaline wings, long and narrow abdomen. Body color of male and female varies markedly with age, with immature males and females with purplish-blue markings, which become yellow and greenish blue in the male (Fig. 11 a, g – i) and yellow and orange in the female (Fig. 11 f). Cerci are strongly curved downward and paraprocts are thin and somewhat curved upward (Fig. 11 b – c). Male genital ligula is slender (Fig. 11 d – e). Female Cryptophaea vietnamensis is characterized by remarkably large orange-colored markings on the mesepisternum (Fig. 11 f). The shape and coloration of thoracic pattern also vary in males; this variation is to some extent geographical: males in the north (for instance from Cuc Phuong, Ba Vi, Xuan Son and Tam Dao National Parks) or from the Central Highlands (e. g. from Kon Ka Kinh National Park) have a U-shaped mark on the mesepisternum formed by a dorsal stripe and a humeral stripe connected anteriorly (Fig. 11 g – i), but the dorsal stripe is missing and the humeral stripe much truncated in specimens from Ba Na or Bach Ma in central Vietnam (Fig. 11 a). Males from the north have bluish-green markings when mature (Fig. g – h), but yellowish in males from central Vietnam, for instance from Ba Na, Bach Ma and Kon Ka Kinh (Fig. 11 a, i).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFEAEC09B594FC6BFE57D2FE.taxon	distribution	Distribution. Vietnam (Cao Bang, Bac Kan, Lang Son, Phu Tho, Hoa Binh, Vinh Phuc, Ha Noi, Ninh Binh, Thanh Hoa, Quang Binh, Quang Tri, Thua Thien-Hue, Da Nang, Kon Tum and Gia Lai Provinces), China (Guangxi Province) (Wilson & Reels 2003), Laos (Bolikhamxay and Houaphan Provinces) (Yokoi & Kano 2002, Hämäläinen 2003, this study).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF4EC09B594FCC5FD33D52B.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Suoi Cun, Cao Bang Prov., 20. V. 2015, Q. T. Phan leg. (PQTC); 1 ♂ (teneral), Xuan Son National Park, Phu Tho Prov., 19. V. 2014, H. Karube leg. (PQTC). Other materials confirmed by field observations. [Vietnam] Some individuals, Cao Bang Prov., V, VI. 2015, T. Kompier; Some individuals, Bac Kan Prov., VII. 2013, VI, VII. 2014, IV. 2015, T. Kompier; Some individuals, Lang Son Prov., VI. 2014, VI. 2015, T. Kompier; 1 ♂, Bac Giang Prov., 22. VI. 2015, T. Kompier; 25 ♂ 1 ♀, Bac Giang Prov., 14. VII. 2017, T. Kompier; 5 ♂, Yen Bai Prov., 21. VI. 2015, T. Kompier; Some individuals, Phu Tho Prov., V, VII. 2014, IV, V, VI. 2015, VII. 2016, T. Kompier; 3 exs, 9. VII. 2017, Bac Kan Prov., T. Kompier; several exs, V. 2017, Phu Tho Prov, T. Kompier. Notes. Male has dark body, with thin pale lines over the nodes of the abdomen. Male wings are black on the basal two-thirds between the base and nodus and with black apices from the middle of the pterostigma outward, the area in between being pale translucent amber (Fig. 12 a). Female also has body blackish but with more distinct yellow markings. Female wings are wholly translucent amber, slightly more darkened at the tip (Fig. 12 b).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF4EC09B594FCC5FD33D52B.taxon	distribution	Distribution. Vietnam (Cao Bang, Bac Kan, Lang Son, Bac Giang, Yen Bai, Phu Tho, Hoa Binh [Hämäläinen et al. 2015] and Ninh Binh [Do & Dang 2007; Hämäläinen et al. 2015] Provinces), China (Yunnan, Guangxi and Hainan Provinces) (Hämäläinen et al. 2015).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF4EC0AB594F928FF5FD4DF.taxon	materials_examined	Materials examined. [Vietnam] 5 ♂ 2 ♀, Bhalee, Tay Giang District, Quang Nam Prov., 27. V. 2015, Q. T. Phan leg. (PQTC); 2 ♂, Bhalee, Tay Giang District, Quang Nam Prov., 30. IV. 2016, T. Kompier leg. (TKC); 1 ♂, Bhalee, Tay Giang District, Quang Nam Prov., 17. IX. 2015, H. Karube leg. (KPM); 3 ♂, H’mun, Bar Maih, Chu Se District, Gia Lai Prov., 24. IV. 2016, Q. T. Phan leg. (PQTC). Other materials confirmed by field observations. [Vietnam] 1 ♂, Ha Tinh Prov., 13. VI. 2015, T. Kompier; Some individuals, Quang Binh Prov., IV, V, VI. 2016, T. Kompier; Some individuals, Quang Tri Prov., V. 2016, T. Kompier; Some individuals, Quang Nam Prov., IX. 2015, IV, V, VI. 2016, T. Kompier; Some individuals, Cat Tien National Park, Dong Nai Prov., VIII. 2014, T. Kompier; 5 exs, 11. V. 2017, Dong Nai Prov., T. Kompier; 6 exs, 14. V. 2017, Thua Thien-Hue Prov., T. Kompier. Notes. Male of this species can be distinguished from all Dysphaea species by wings that are entirely reddish brown or brown, with somewhat darkened apices (Fig. 12 c). Females of Dysphaea gloriosa have a complete large yellow loop on the mesepisternum (Fig. 12 d).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF4EC0AB594F928FF5FD4DF.taxon	distribution	Distribution. Vietnam (Ha Tinh, Quang Binh, Quang Tri, Thua Thien-Hue, Quang Nam, Gia Lai, Lam Dong [Asahina 1969], Dong Nai and Ho Chi Minh [Asahina 1969] Provinces), Laos (Oudomxai, Vientiane and Attapeu Provinces) (Yokoi & Mitamura 1995, Yokoi & Souphanthong 2005, Sasamoto et al. 2011), Cambodia (Koh Kong, Pursat, Preah Sihanouk, Stung Treng, Ratanakiri and Mondulkiri Provinces) (Kosterin 2010, 2014, 2015, 2016, 2017), Thailand (Mae Hong Son, Chiang Mai, Ching Rai, Phitsanulok, Phetchabun, Loei, Chaiyaphum, Nakhon Rstchasima, Ubon Ratchathai, Kanchanaburi, Prachuap Khiri Khan and Saraburi Provinces) (Hämäläinen 2017), China (Yunnan and Hainan Provinces) (Hämäläinen et al. 2015), India (Assam and Meghalaya) (Hämäläinen et al. 2015).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF6EC0BB594FF10FC97D07E.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Ha Giang Prov., 1. VII. 2014, T. Kompier leg. (TKC); 2 ♂, Suoi Cun, Cao Bang Prov., 20. V. 2015, Q. T. Phan leg. (PQTC). Other materials confirmed by field observations. [Vietnam] Some individuals, Cao Bang Prov., VI. 2014, V, VI. 2015, T. Kompier; Some individuals, Quang Binh Prov., IV, V, VI. 2016, V, VI. 2017, T. Kompier. 1 ♂, Thua Thien-Hue Prov., 14. V. 2017, T. Kompier. Notes. Fully mature males of Dysphaea haomiao can be separated from all Dysphaea species by their wholly black wings (Fig. 12 e). In semi-mature specimens, the wings are dark brownish; they are therefore difficult to separate from those of mature D. gloriosa (Hämäläinen pers. comm.). Females are similar to Dysphaea gloriosa in body color pattern, but have all pale metepimeron (Fig. 12 f). In Vietnam, Dysphaea haomiao was previously recorded only in Cao Bang Prov., northern Vietnam (Hämäläinen 2012), which is close to the border with China.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF6EC0BB594FF10FC97D07E.taxon	distribution	Distribution. Vietnam (Ha Giang, Cao Bang, Thua Thien-Hue and Quang Binh Provinces), China (Guizhou, Yunnan and Guangxi Provinces) (Hämäläinen et al. 2015).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF6EC0CB594FBFDFCB1D2FE.taxon	materials_examined	Materials examined. [Vietnam] 2 ♂, Tu Le, Yen Bai Prov., 19. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂, Nam Bung, Yen Bai Prov., 11. V. 2014, T. Kompier leg. (TKC); 1 ♀, Xuan Son National Park, Phu Tho Prov., 16. IX. 2015, Q. T. Phan leg. (PQTC); 4 ♂ 2 ♀, Cham Chu, Ham Yen, Tuyen Quang Prov., 12. VII. 2015, Hoang Vu Tru leg. (PQTC). [China] 2 ♂, Chebaling, Shixing, Shaoguan, Guangdong Prov., 04. X. 2008, X. Yu leg. (PQTC); 1 ♂ 1 ♀, Shenzeng, Guangdong Prov., 9 – 10. VII. 2016, F. Hayashi leg. (FHC); 1 ♂ 1 ♀, Hong Kong, 11 – 12. VII. 2016, F. Hayashi leg. (FHC); 2 ♂, Damingshan, Guangxi Prov., 6. VI. 2014, F. Hayashi leg. (FHC); 1 ♂, Jinhuacha, Guangxi Prov., 7. VI. 2014, F. Hayashi leg. (FHC); 1 ♂ 1 ♀, Shiwandashan, Guangxi Prov., 9. VI. 2014, F. Hayashi leg. (FHC). Other materials confirmed by field observations. [Vietnam] Some individuals, Ha Giang Prov., VII. 2014, T. Kompier; Some individuals, Cao Bang Prov., VI, VII. 2014, V, VI, IX, X. 2015, T. Kompier; Some individuals, Lang Son Prov., VI. 2014, V, VI, VII, X. 2015, T. Kompier; 15 exs, Thai Nguyen Prov., 15. VI. 2015, T. Kompier; 1 ♂, Bac Giang Prov., 22. VI. 2015, T. Kompier; Some individuals, Yen Bai Prov., V, VI, VII. 2014, V, VI, VII, X. 2015, VII. 2016, T. Kompier; Some individuals, Xuan Son National Park, Phu Tho Prov., X. 2013, V, VI, VII, IX, X, XI. 2014, V, VI, VII, VIII, IX, X. 2015, V, VII, VIII. 2016, T. Kompier; 5 exs, Hoa Binh Prov., 27. VI. 2014, T. Kompier; Some individuals, Tam Dao National Park, Vinh Phuc Prov., VIII, IX. 2013, VI, VII. 2014, VII. 2015, T. Kompier; 25 exs, Vinh Phuc Prov., 16. VIII. 2015, T. Kompier; 4 exs, Ba Vi National Park, Ha Noi City, 14. IX. 2013, T. Kompier; 15 exs, Quang Ninh Prov., 25. VI. 2017, T. Kompier; 50 exs, 8 – 9. VII. 2017, Bac Kan Prov., T. Kompier. Notes. This species is widely distributed in northern Vietnam and is often abundant. Synthorax of male black with yellow stripes that become entirely obscured with age (Fig. 13 a). Male FW are hyaline, but the HW are black from the nodus outward for about three-fifths of the wing distal of the nodus, the apex hyaline. In the female the wings are tinged amber (Fig. 13 b).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF6EC0CB594FBFDFCB1D2FE.taxon	distribution	Distribution. Vietnam (Ha Giang, Cao Bang, Bac Kan, Lang Son, Thai Nguyen, Bac Giang, Quang Ninh, Yen Bai, Phu Tho, Hoa Binh, Tuyen Quang, Vinh Phuc, Ha Noi and Ha Tinh Provinces) (Do and Dang 2007, this study), China (Hubei, Zhejiang, Jiangxi, Fujian, Guangdong, Hong Kong, Guangxi and Yunnan Provinces) (van Tol & Rozendaal 1995, Hämäläinen 2004, Zhang 2010).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF1EC0DB594F9B1FE88D6DD.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Nam Bung, Yen Bai Prov., 1. VI. 2014, T. Kompier leg. (TKC); 1 ♂, Nam Bung, Yen Bai Prov., 10. V. 2014, T. Kompier leg. (TKC); 3 ♂, Vu Quang National Park, Ha Tinh Prov., 7. IX. 2015, Q. T. Phan leg. (PQTC); 1 ♂, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, Q. T. Phan leg. (PQTC); 3 ♂, Bhalee, Tay Giang District, Quang Nam Prov., 18. IX. 2015, Q. T. Phan leg. (PQTC); 2 ♂, Tr’hy, Tay Giang District, Quang Nam Prov., 20. VII. 2017, Q. T. Phan leg. (PQTC); 1 ♂, Quang Nam Prov., 20. VI. 2016, T. Kompier leg. (TKC); 1 ♂ 1 ♀, Mang Den, Kon Plong District, Kon Tum Prov., 20. IX. 2015, F. Hayashi leg. (FHC). [China] 2 ♂ 2 ♀, Xishuangbanna, 1300 m, Yunnan Prov., 3. IX. 2006, X. Yu leg. (PQTC). [Laos] 1 ♂ 1 ♀, Xam Neua, Houaphan Prov., 9. VI. 2017, X. Liu leg. (FHC). [Malaysia] 2 ♂ 5 ♀, Ipoh, Perak state, Malaysia, 28. IV. 2012, F. Hayashi leg. (FHC); 1 ♂, Penang Hill, Penang, Malaysia, 7. III. 2014, Y. Kamimura leg. (FHC). Other materials confirmed by field observations. [Vietnam] Some individuals, Yen Bai Prov., IV, V, VII. 2014, IV, V, VI. 2015, VII. 2016, T. Kompier; 20 exs, Hoa Binh Prov., 12. V. 2015, T. Kompier; Some individuals, Thanh Hoa Prov., V, VI. 2015, T. Kompier; Some individuals, Quang Nam Prov., IX. 2015, VI. 2016, T. Kompier; 2 exs, 4. VI. 2017, Quang Binh Prov., 15 exx, 3. IX. 2016, T. Kompier; Quang Binh Prov., T. Kompier; 25 exs, 8. IX. 2016, Quang Binh Prov., T. Kompier. Notes. This species is distributed in northern and central Vietnam. Male wings are pale orange colored, but the apices are hyaline. Bodies of male and female are shown in Figure 17 a and 17 b, respectively. Asahina (1977) noted that male specimens taken in Malaysia and southern Thailand have an entirely pale brownish [sic] HW, but that in Laotian males, the brownish [sic] area of HW is restricted before the pterostigma, although a clear geographical differentiation using this character seems difficult. We also confirmed this difference between Malaysia and Laos. In Vietnam and China, all male specimens examined have a HW similar to that observed in Laotian males (Fig. 17 a). Male genital ligula has laterally curved flagella typically seen in other Euphaea species, but these are relatively narrow and elongated (Fig. 17 c).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF1EC0DB594F9B1FE88D6DD.taxon	distribution	Distribution. Vietnam (Lai Chau, Yen Bai, Hoa Binh, Thanh Hoa, Nghe An, Ha Tinh, Thua Thien-Hue, Quang Nam and Kon Tum Provinces), China (Yunnan Province) (Zhang 2010), Laos (Phongsali, Luang Namtha, Oudomxay, Houaphan, Vientiane and Attapeu Provinces) (Fraser 1933, Asahina 1977, Yokoi & Mitamura 1995, Yokoi 1999, Yokoi & Souphanthong 2004, 2005, Sasamoto et al. 2009, this study), Thailand (most of the country, except Central Plains and North-east) (Hämäläinen 2017), Myanmar (Shan and Bago Provinces [Schmidt 1964], unknown in detail [Asahina 1970]), Peninsular Malaysia (Johor, Kelantan, Pahang, Penang, Perak, Perlis and Selangor States) (Lieftinck 1954, Laidlaw 1902, 1903, 1924, 1931, Fraser 1942, Hämäläinen et al. 1996, Kitagawa 1997, Dow et al. 2016), Nepal (Kathmandu Valley) (Vick 1989), Bangladesh (Chittagong and Sulhet divisions) (Khan 2017 a), India (Meghalaya [Lahiri 1987], Arunachal Pradesh, Assam, Manipur, West Bengal and Mizoram [Mitra 2002]).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	materials_examined	Holotype. ♂, Bao Loc, Lam Dong Prov., 17. VI. 2016, T. Kompier leg. Deposited at Zoological Collection of Systematic Zoology Institute in Tokyo Metropolitan University, Tokyo, Japan (TMUZ).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	description	Male paratypes. 1 ♂ the same location, date and collector as holotype (TMUZ); 2 ♂, Bao Loc, Lam Dong Prov., 15 – 17. VI. 1996, H. Karube leg. (KMP); 1 ♂, Bao Loc, Lam Dong Prov., 1. VI. 2002, H. Karube leg. (KMP);	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	materials_examined	Other materials examined. 1 ♂, Nam Ka Nature Reserve, Dak Lak Prov., 8. X. 2017, Hoang Quang Duy leg. (PQTC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	description	Female paratype. 1 ♀, Bao Loc, Lam Dong Prov., 17. VI. 2016, T. Kompier leg. (TMUZ).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	etymology	Etymology. The specific name “ sanguinea ” refers to the clear-cut red coloration of abdomen segments S 2 – 6.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	description	Description of holotype. Head (Fig. 17 h). Labrum, postclypeus, anteclypeus, genae, base of mandibles, antennae, and dorsal surface of head all black. Compound eyes dark chestnut when alive. Thorax (Fig. 17 f). Prothorax black but middle lobe with a pair of orange marks. Synthorax with black mesepisternum with narrow but distinct orange dorsal stripe and antehumeral stripe. Mesepimeron black with distinct orange stripe over its center, slightly hooked downwards at its distal end. Metepisternum and metepimeron red, with black line over centers and covering metapleural suture. Mesinfraepisternum black with some red, metinfraepisternum red with black margin. Legs black. Coxae and trochanters black. Wings (Fig. 17 f). Strongly colored reddish orange from base to proximal third of outer wing, thereafter gradually paler amber. Veins are similarly reddish turning amber, but largest veins dark. FW has 30 Ax and 42 Px, HW 26 Ax and 34 Px. Pterostigma dark brown, covering 7 cells. Abdomen. Abdominal S 2 – 6 bright red, ringed black at posterior margins, progressively more distinctly so distally; S 7 – 10 black. Genital ligula (Fig. 17 c). Like E. ochracea. Vesicle coarsely grooved, similar to E. ochracea. Anal appendages (Fig. 17 j). Black, of usual type, with very short paraprocts in the form of small hooks and double lobed cerci. Cerci with two ventral lobes, the first of which has its proximal edge almost straight and perpendicular to cercus. Measurements (in mm). HW 27; abdomen (incl. appendages) 32. Variation in paratype males. Four paratypes show little morphological variation, excluding size; 26.5 – 28.5 mm in HW length and 32 – 33.5 mm in abdomen including appendages. Description of paratype female. Head (Fig. 17 i). Black, excluding the yellow markings on labrum, base of mandibles, frons at eye margins, and spots between base of antennae and lateral ocelli. Antennae black. Compound eyes brown. Thorax (Fig. 17 g). Anterior lobe of prothorax black with two small yellow dots; middle lobe largely black except for two lateral yellow markings; posterior lobe simple, its distal margin smoothly rounded and broadly yellowish; propleuron black with some yellow marking laterally. Synthorax black with yellow marking like male, but mesinfraepisternum yellow with some black, and metinfraepisternum yellow. Legs dark grey, with a yellow stripe on each inner femur. Coxae and trochanters dark grey. Wings (Fig. 17 g). Weakly yellowish, particularly at basal part. Veins dark. FW 25 Ax and 32 Px, HW 19 Ax and 26 Px. Pterostigma brown, covering 7 cells. Abdomen (Fig. 17 g). Black, with lateral yellow stripes in two rows (lower one is shorter than upper one) across S 1 – 6, but only a small anterior mark on S 7 and no stripe on S 8. S 9 a posterolateral oval yellow spot. S 10 and cerci black. Ovipositor yellowish, but black on ventral valvula and stylus. Measurements (in mm). HW 27.5; abdomen (incl. appendages) 28.5.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	discussion	Remarks. Males of Euphaea sanguinea sp. nov. resemble those of E. ochracea, the geographic variability of which is complicated. Euphaea brunnea Selys, 1879 was described from specimens from Khasi Hills, Meghalay, NE India. Hämäläinen (2016, p. 26 note 41) discusses the uncertainty of the status of Euphaea brunnea and whether it qualifies as a subspecies of E. ochracea. Superficially, specimens from central and northern Thailand as well as northern Vietnam resemble brunnea better than ochracea (Hämäläinen in litt.). In view of the uncertainty of the validity of the taxon brunnea as a subspecies of Euphaea ochracea we refrain from the subspecific identification of the specimens of E. ochracea from Vietnam. Males of Euphaea sanguinea can be distinguished by the cerci. These differ from those of Euphaea ochracea (Fig. 17 e) by having a well-developed triangular ventral lobe at the base (Fig. 17 j). Euphaea sanguinea also differs by the relatively narrow area of reddish orange in HW (Fig. 17 f) compared to both topotypical material (which has wings almost completely unicolourous) and compared to material of E. ochracea from Vietnam (Fig. 17 a) and by the clear-cut reddish pattern on S 2 – 6 compared to the specimens of E. ochracea occurring in Laos and Vietnam, although topotypical material has distinctly redder abdomen, if not as clear-cut (Fig. 17 a, f). Females of Euphaea sanguinea can be distinguished from those of E. ochracea by the pattern of their abdominal yellow markings with much wider stripes on S 1 – 6 in the former (Fig. 17 g), but narrower stripes on S 1 – 7 in the latter species (Fig. 17 b), although this is to some extent an age-dependant character and as such should be treated with care. Although Fraser (1934) and Asahina (1986) mention a yellow stripe across the antefrons for Euphaea ochracea, at least the specimens from Vietnam we were able to inspect have this stripe interrupted, although not as widely as in E. sanguinea (Fig. 17 d, i). To some extent the width of the gap may also be age-dependant, but it appears that female Euphaea sanguinea generally has relatively less yellow marking on the frons. The structure of the prothorax appears to be similar for the females of both Euphaea sanguinea and E. ochracea. Earlier, Kosterin (2016) provided photos of damselflies identified as ‘ Euphaea ochracea ’ from Mondulkiri Prov., Cambodia, and pointed out that the five collected female specimens had " entirely black postclypeus and the pale marking on the anteclypeus broadly interrupted. " This was erroneous wording. Proper wording should have been " entirely black clypeus and pale marking on the antefrons broadly interrupted " (Kosterin, pers. comm.), which is in line with our own material from Vietnam. He put “? ssp. ” after the species name to indicate that those specimen could represent an undescribed subspecies, but refrained from nominating the Cambodian specimens as a new taxon. The abdomen pattern of distinctly red S 2 – 6 displayed in the photos of Cambodian ‘ Euphaea ochracea’ is identical to that of E. sanguinea sp. nov., and the same holds true of the HW coloration (Fig. 17 f in this paper and Fig. 25, p. 25 in Kosterin 2016). Therefore, it can be safely assumed that ‘ Euphaea ochracea’ from Cambodia in fact were E. sanguinea sp. nov.. According to M. Hämäläinen (in litt.) the specimens from Lam Dong (Bao Loc) and Dong Nai (Cat Tien National Park) recorded as Euphaea ochracea by Do & Dang (2007) also refer to E. sanguinea; Hämäläinen himself has also collected specimens of Euphaea sanguinea from these provinces.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF0EC0FB594FA79FEEED063.taxon	distribution	Distribution. Vietnam (Dak Lak, Lam Dong and Dong Nai Provinces), Cambodia (Mondulkiri Province) (Kosterin 2016).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFCEC02B594F99EFB05D1DE.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Phu Quoc Isl., Kien Giang Prov., 30. XII. 2015, T. Kompier leg. (TKC); 2 ♂, same location and collector, 14. IV. 2016 (TKC). Other materials confirmed by field observations. [Vietnam] 6 exs, 19 – 20. VIII. 2016, Phu Quoc Isl., Kien Giang Prov., T. Kompier. Notes. This species is newly recorded for Vietnam, although Bui (2007) published the same taxon first as Euphaea ochracea. Hämäläinen (1985) described Euphaea pahyapi from the peninsular part of Thailand based on male specimens. Asahina (1985) also described Euphaea khaochongensis from another province of the same area, but this was treated as a junior synonym of E. pahyapi by Pinratana et al. (1988) and in Hämäläinen & Pinratana (1999). Euphaea pahyapi can be distinguished from all Vietnamese Euphaea species by the unique completely and evenly amber-colored wings of the male (Fig. 18 d). Color pattern of the head is variable, entirely black as in the original description (Hämäläinen 1985) or with dirty blue markings as in Asahina's (1985) description and our specimens from Vietnam (Phu Quoc Island) (Fig. 19 b). Abdomen and anal appendages are as in Euphaea masoni, with hairs only on S 3 (Fig. 15 d). Vesicle of Euphaea pahyapi differs from that of E. masoni by being heart-shaped, pointed at its posterior margin (Fig. 18 f) whereas it is ax-shaped with the posterior margin rounded in E. masoni (Fig. 18 e). Female of this species is still undescribed. The record of Euphaea ochracea from Kbal Chhay Cascades of Preah Sihanouk Province, Cambodia in Kosterin et al. (2012) is a misidentification and concerns in fact E. pahyapi (Kosterin 2016, and pers. comm.)	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFCEC02B594F99EFB05D1DE.taxon	distribution	Distribution. Vietnam (Phu Quoc Island), Thailand (Ranong, Krabi, and Trang Provinces) (Hämäläinen 2017), Cambodia (Preah Sihanouk Province) (Kosterin et al. 2012, and Kosterin pers. comm.).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFEEC03B594FBF1FBB8D519.taxon	materials_examined	Materials examined. No material available to the authors. Notes. A large sized, brownish winged species, somewhat resembling Euphaea opaca Selys, 1853. According to M. Hämäläinen (in litt.) there is also one male specimen of Euphaea superba from ‘ Tonkin’ (without further details) at NRS Stockholm. The specimen originates from Coll. F. Ris, and includes his identification label ‘ Euphaea spec. nov. ’ It is possible that this specimen was also purchased from Hans Fruhstorfer. Obviously this is a very rare species in northern Vietnam. According to information received from Haomiao Zhang and M. Hämäläinen (in litt.), in China Euphaea superba occurs in Guangxi and Guizhou; the published E. superba records from Guangdong and Hong Kong (cf. Wilson & Zaifu 2007) refer to E. opaca.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFEEC04B594F944FF5FD6B9.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Xuan Son National Park, Phu Tho Prov., 25. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂, Xuan Son National Park, Phu Tho Prov., 13. IV. 2014, T. Kompier leg. (TKC); 1 ♂ 1 ♀, Bhalee, Tay Giang District, Quang Nam Prov., 17. IX. 2015, Q. T. Phan leg. (PQTC); 2 ♂, Bhalee, Tay Giang District, Quang Nam Prov., 17. IX. 2015, F. Hayashi leg. (FHC); 2 ♂ 1 ♀, Quang Nam Prov., 21. VI. 2016, T. Kompier leg. (TKC); 5 ♂, Ba To, Quang Ngai Prov., 7. IX. 2017, Pham Thi Nhi leg. (PQTC). [China] 2 ♂, Jinhuacha, Guangxi Prov., 7. VI. 2014, F. Hayashi leg. (FHC). Other materials confirmed by field observations. [Vietnam] 40 exs, Thai Nguyen Prov., 15. VI. 2015, T. Kompier; Some individuals, Xuan Son National Park, Phu Tho Prov., IV, V, VI. 2014, III, IV, V, VI. 2015, IV, V. 2016, T. Kompier; Some individuals, Tam Dao National Park, Vinh Phuc Prov., V, VI. 2014, T. Kompier; 60 exs, Vinh Phuc Prov., 12. IV. 2015, T. Kompier; 12 exs, Hoa Binh Prov., 27. VI. 2014, T. Kompier; Some individuals, Nghe An Prov., V, VI. 2015, T. Kompier; Some individuals, Ha Tinh Prov., V, VI. 2015, V. 2016, T. Kompier; Some individuals, Quang Binh Prov., IV, V, VI. 2016, T. Kompier; Some individuals, Quang Tri Prov., V, VI. 2016, T. Kompier; Some individuals, Thua Thien-Hue Prov., V. 2016, T. Kompier; Some individuals, Quang Nam Prov., IV, V, VI. 2016, T. Kompier; 1 ♂, Gia Lai Prov., 13. V. 2017, T. Kompier. Notes. Euphaea guerini was originally described by Rambur (1842) based on specimens from southern Vietnam, but the description did not contain any figures of structures. Later, Selys & Hagen (1854) provided a more detailed description of Rambur’s holotype, including a good illustration of the appendages (see Fig. 2, pl. 14 in Selys & Hagen 1854). The shape of S 10 (Fig. 20 f) and the small size of the Vietnamese specimens is in line with this description and supports the identification of the material presented in this study as Euphaea guerini and not E. saola sp. nov.. Male of Euphaea guerini has black body and extensively darkened wings. FW are hyaline both basally and apically. HW are very dark with metallic blue on the underside covering about two-thirds of the wing, and with green flash on basal anal area on the upperside (Fig. 14 c). Male S 9 bears a bundle of hairs (Fig. 15 b). In female, wings are hyaline with orange-yellowish area basally, and head, thorax and abdomen marked yellowish as in Figure 16 e. This species has not been recorded in Thailand (Hämäläinen 2017) and Cambodia (Kosterin 2014, 2016), although Martin (1904) and then Asahina (1985) mentioned Cambodia as a locality of this species without giving a specific location. Yokoi & Kano (2002) and Yokoi & Souphanthong (2005) reported it from central and southern Laos. However, in Cambodia, central to southern Laos, and central Vietnam, the past records of Euphaea guerini may include E. saola sp. nov.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFEEC04B594F944FF5FD6B9.taxon	distribution	Distribution. Vietnam (Thai Nguyen, Phu Tho, Vinh Phuc, Hoa Binh, Nghe An, Ha Tinh, Quang Binh, Quang Tri, Thua Thien-Hue, Quang Nam, Quang Ngai, Lam Dong and Khanh Hoa Provinces), China (Guangxi Province) (Wilson & Reels 2003), Laos (Bolikhamxay and Attapeu Provinces) (Yokoi & Kano 2002, Yokoi & Souphanthong 2005).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	materials_examined	Holotype. ♂, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, Q. T. Phan and F. Hayashi leg. Deposited at Zoological Collection of Systematic Zoology Institute in Tokyo Metropolitan University, Tokyo, Japan (TMUZ). Male paratypes. 4 ♂, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, Q. T. Phan, F. Hayashi and H. Karube leg. (FHC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	description	Female paratype. 1 ♀, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, F. Hayashi leg. (FHC). Other materials examined. [Vietnam] 2 ♂, Quang Binh Prov., VI. 2016, T. Kompier leg. (TKC); Quang Tri Prov., VI. 2016, T. Kompier leg. (TKC); Thua Thien-Hue Prov., VI. 2016, T. Kompier leg. (TKC); 3 ♂ 1 ♀, A Luoi Nature Reserve, Thua Thien-Hue Prov., 18. IX. 2015, F. Hayashi leg. (FHC); 3 ♂, Dong Giang District, Quang Nam Prov., 26. V. 2015, Q. T. Phan leg. (PQTC); 3 ♂ 1 ♀, Quang Nam Prov., 21. VI. 2016, T. Kompier leg. (TKC); 1 ♂, Ba Na Nature Reserve, Da Nang city, 22. V. 2017, Q. T. Phan leg. (PQTC); 4 ♂ 1 ♀, Chu Mom Ray National Park, Kon Tum Prov., 22. V. 2017, Q. T. Phan leg. (PQTC); 10 ♂, Hon Ba Nature Reserve, Khanh Hoa Prov., 16. IV. 2017, Q. T. Phan leg. (PQTC); 4 ♂, Bach Ma National Park, Thua Thien-Hue Prov., 28. VI. 2017, Q. T. Phan leg. (PQTC); 8 ♂, Chu Yang Sin National Park, Dak Lak Prov., 30. IV. 2017, Hoang Quang Duy leg. (PQTC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	materials_examined	Other materials confirmed by field observations. [Vietnam] Some individuals, Bach Ma, Thua Thien-Hue Prov., 5 – 8. VIII. 2016, T. Kompier.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	etymology	Etymology. The specific name “ saola ” of this species is derived from the name of the bovid “ Saola ” (Pseudoryx nghetinhensis Dung, Giao, Chinh, Tuoc, Arctander & MacKinnon, 1993). This is one of the world’s rarest large mammals, a forest-dwelling bovine found only in the Truong Son mountain range of Vietnam and Laos. The type locality of Euphaea saola sp. nov. is A Luoi Nature Reserve which is a part of the Saola Conservation Area, central Vietnam. The general distribution of the new species largely coincides with that of this extraordinary mammal.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	description	Description of holotype. Head, prothorax, synthorax, and legs (Fig. 20 a). Entirely black excluding some narrow yellow stripes along the border of mesepimeron and metepisterum and on lower margin of metepimeron. Wings (Fig. 14 d). Similar to those of E. guerini with most of FW area darkened, excluding the basal part of the wing (but covering all cells along the subcosta), and the apical one-sixth, although the apical margin of the FW is also darkened. HW are black with metallic blue covering a large part of their underside, and with metallic green on the upperside, as in E. guerini. FW has 28 – 29 Ax and 32 – 33 Px, and HW have 22 – 23 Ax and 35 – 37 Px. The cubital space has 2 – 3 crossveins in both wings. Abdomen. Entirely black. Lateroventral margin of S 3 and S 7 – 8 with fine setae in addition to the tuft of long setae on the base of S 9 like E. guerini (Fig. 15 a). Dorsum of S 10 raised into large carinal spine posteriorly and with a small hump near its anterior margin (Fig. 20 b). Genital ligula. With two thick flagella, perpendicular to terminal segment as in Figure 20 c. Anal appendages. Typical of the genus with cerci short and robust, paraprocts are very short, slightly curved upward (Fig. 20 b). Measurements (in mm). HW 29; abdomen (incl. appendages) 37. Variation in paratype males. Four paratypes show little morphological variation, excluding size; 27.5 – 29.5 mm in HW length and 36 – 38 mm in abdomen including appendages. Description of paratype female. Head (Fig. 20 d). Postclypeus, frons, antennae, and the dorsum of head matte black. Anteclypeus shining black. Labrum and base of mandibles dark yellow but margin and mid-dorsal part black. Genae dark yellow and this extends to the level of antennae. Thorax (Fig. 16 e). Anterior lobe of prothorax entirely black; middle and posterior lobes black with tiny orange spots; middle lobe raised into two large separately humps; distal margin of posterior lobe rounded, simple structurally (Fig. 18 g). Synthorax black with narrow orange stripes as follows: mesepisternum has two separated narrow stripes on either side; mesepimeron entirely black; metepisternum and metepimeron both with two yellow stripes along distal and lower margins. Legs. Black. Wings. Hyaline tinted amber on proximal half of FW and complete HW. FW with 28 – 29 Ax and 31 – 32 Px, HW with 21 Ax and 29 Px. Cubital space with 1 – 3 crossveins in all wings. Abdomen (Fig. 16 e). Black with lateral yellow markings as follows: S 1 with a large spot, S 2 – 3 with a very narrow stripe, S 4 – 5 with only tiny oval posterior spot, and S 6 – 10 and ovipositor black. Measurements (in mm). HW 29; abdomen (incl. appendages) 33.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	discussion	Remarks. Euphaea saola sp. nov. is very similar to the population of E. guerini in Vietnam with similar wingcolor pattern of the male, but can be distinguished by more distinct dark apical margin and more distinct hyaline base in FW (Fig. 14 d) compared to E. guerini (Fig. 14 c). Abdominal segments S 3 and S 8 bear long setae in Euphaea saola (Fig. 15 a), but very short setae in E. guerini (Fig. 15 b). In Euphaea saola, the dorsum of S 10 is raised in two places: there is a small hump in lateral view on the anterior part, but posteriorly it rises somewhat obliquely upward (Fig. 20 b) forming a conspicuous carinal spine. S 10 of Euphaea guerini lacks the anterior hump and the large posterior carinal spine rises strongly upwards, almost perpendicular to the abdomen (Fig. 20 e). Cerci are short and robust, the posterior dorsal spine of S 10 extending beyond their base posteriorly in lateral view in Euphaea saola (Fig. 20 b), but cerci of E. guerini are narrower, petiolated at base, and the dorsal spine does not extend posteriorly of their base, so they are visible in dorsal view (Fig. 20 e). Vesicle of Euphaea saola heartshaped, pointed at its posterior margin (Fig. 18 a, b), but it is ax-shaped, with posterior margin rounded in E. guerini (Fig. 18 c). The shape of the posterior lobe of the prothorax in females of Euphaea saola differs markedly from that of E. guerini by the smoothly rounded lateral edges and minor indentation of the posterior margin (Fig. 18 g), while the lateral edges curve out and backwards in E. guerini, and the posterior margin is completely round centrally (Fig. 18 h). In addition, (i) thorax black with very narrow stripes in E. saola (Fig. 16 e), but stripes relatively broad in E. guerini (Fig. 16 d); (ii) abdomen black with narrow yellow stripes on S 1 – 3, tiny spots on S 4 – 5, and entirely black on other segments in E. saola (Fig. 16 e), but with stripes on S 1 – 6 and a small yellow spot on S 9 in E. guerini (Fig. 16 d); and (iii) wings entirely dark amber in E. saola, but hyaline with pale yellow color in E. guerini. It is difficult to establish what published records / info of Euphaea guerini refer to E. saola. Van Tol & Rozendaal (1995) provided figures of the last abdominal segments and vesicle of Euphaea guerini from central Vietnam, but they did not specify the locality of each specimen. Figure 20 of ‘ Euphaea guerini ’ in van Tol & Rozendaal (1995) matches E. saola based on the resemblance of the dorsal prominence on S 10, but their Fig. 21 of vesicle is similar to that of E. guerini (Fig. 18 c) with apical margin rounded, not pointed as in E. saola (Fig. 18 a, b). Hämäläinen (in litt.) also confirmed that ‘ Euphaea guerini ’ from Lak Sao, Bolikhamxay Prov., Laos by Karjalainen & Hämäläinen (2013) actually refers to E. saola. Similarly, earlier published records of ‘ Euphaea guerini ’ in Cambodia, central to southern Laos, and central Vietnam could likely include or refer to E. saola (e. g. Fig. 44, p. 31 in Phan et al. 2011).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFF9EC07B594F9A5FC43D236.taxon	distribution	Distribution. Vietnam (Ha Tinh [Hämäläinen in litt.], Quang Binh, Quang Tri, Thua Thien-Hue, Da Nang, Quang Nam, Quang Ngai [Hämäläinen in litt.], Dak Lak, Gia Lai, Kon Tum and Khanh Hoa [Hämäläinen in litt.] Provinces), Laos (Bolikhamxay Province) (Karjalainen & Hämäläinen 2013).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFAEC38B594FE01FBCAD55B.taxon	materials_examined	Materials examined. [Vietnam] 2 ♂, Ha Giang Prov., 6 – 7. V. 2011, F. Hayashi leg. (FHC); 2 ♂, Ba Be National Park, Bac Kan Prov., 3 – 8. VI. 2012, F. Hayashi leg. (FHC); 1 ♂, Tam Dao National Park, Vinh Phuc Prov., 18. VIII. 2013, T. Kompier leg. (TKC); 1 ♂ 1 ♀, Xuan Son National Park, Phu Tho Prov., 25. V. 2014, Q. T. Phan leg. (PQTC); 1 ♂, Xuan Son National Park, Phu Tho Prov., 13. IV. 2014, T. Kompier leg. (TKC); 3 ♂ 3 ♀, Tan Hoa, Minh Hoa District, Quang Binh Prov., 14. IV. 2016, Q. T. Phan leg. (PQTC); 4 ♂, Ba Na Nature Reserve, Da Nang City, 15. III. 2012, Q. T. Phan leg. (PQTC); 2 ♂ 2 ♀, Bhalee, Tay Giang District, Quang Nam Prov., 17. IX. 2015, F. Hayashi leg. (FHC); 2 ♂, Mang Den, Kon Plong District, Kon Tum Prov., 20. IX. 2015, F. Hayashi leg. (FHC); 2 ♂, H’mun, Bar Maih, Chu Se District, Gia Lai Prov., 24. IV. 2016, Q. T. Phan leg. (PQTC); 3 ♂ 1 ♀, Hoa Phu, Da Nang, 24. IX. 2017, Q. T. Phan leg. (PQTC); 2 ♂, Bao Loc, Lam Dong Prov., 16. III. 2016 (PQTC); 2 ♀, Bao Loc, Lam Dong Prov., 12. VI. 2016, T. Kompier leg. (TKC); 1 ♂, Lam Dong Prov., 16. V. 2016, T. Kompier leg. (TKC); 3 ♂, Ba To, Quang Ngai Prov., 7. IX. 2017, Pham Thi Nhi leg. (PQTC); 3 ♂ 2 ♀, Da Lat, Lam Dong Prov., 31. III. 1962, Inoue leg. (NSMT). [China] 2 ♂, Jinhuacha, Guangxi Prov., 7. VI. 2014, F. Hayashi leg. (FHC). [Laos] 2 ♂, Vientiane, 3. IX. 2015, S. Nomakuchi leg. (FHC); 2 ♂, Xaignabouli Prov., 26. III. 2016, X. Liu leg. (FHC). Other materials confirmed by field observations. [Vietnam] Some individuals, Ha Giang Prov., VII. 2014, T. Kompier; Some individuals, Cao Bang Prov., VI, VII, XII. 2014, IV, V, VI. 2015, T. Kompier; Some individuals, Bac Kan Prov., VII. 2013, VI, VII, VIII, X, XII. 2014, IV, VI, IX. 2015, T. Kompier; Some individuals, Lang Son Prov., XI. 2013, IV, V, VI, X. 2014, IV, V, VI, VII. 2015, VII. 2016, T. Kompier; Some individuals, Bac Giang Prov., VI. 2015, T. Kompier; Some individuals, Lao Cai Prov., VI. 2015, T. Kompier; Some individuals, Yen Bai Prov., IV, VII. 2014, V, VI, X. 2015, VII. 2016, T. Kompier; Some individuals, Xuan Son National Park, Phu Tho Prov., X, XII. 2013, III, IV, V, VI, VII, IX, X, XI. 2014, III, IV, V, VI, VII, VIII, IX, X, XI. 2015, IV, V, VII, VIII. 2016, T. Kompier; Some individuals, Tam Dao National Park, Vinh Phuc Prov., VIII, IX. 2 0 13, IV, V, VI, VII, X. 2014, VII. 2015, III. 2016, T. Kompier; Some individuals, Ha Tay Prov., VI. 2015, T. Kompier; 1 ♂, Ba Vi National Park, Ha Noi City, 14. IX. 2013, T. Kompier; Some individuals, Hoa Binh Prov., VI. 2014, T. Kompier; Some individuals, Thanh Hoa Prov., V, VI. 2015, T. Kompier; Some individuals, Nghe An Prov., V, VI. 2015, T. Kompier; Some individuals, Ha Tinh Prov., V, VI. 2015, V. 2016, T. Kompier; Some individuals, Quang Binh Prov., IV, V, VI. 2016, T. Kompier; Some individuals, Quang Tri Prov., V, VI. 2016, T. Kompier; Some individuals, Thua Thien-Hue Prov., V. 2016, T. Kompier; Some individuals, Quang Nam Prov., IX. 2015, IV, V, VI. 2016, T. Kompier; Some individuals, Gia Lai Prov., VI. 2016, T. Kompier; Some individuals, Lam Dong Prov., V, VI. 2016, V. 2017 T. Kompier; 3 exs, Quang Ninh Prov., 25. VI. 2017, T. Kompier; Some individuals, Dong Nai Prov., VIII, XI. 2014, II. 2015, II, 2016, I. 2017, T. Kompier. Notes. Earlier authors, such as Selys (1879) and Martin (1904), correctly ranked Euphaea masoni and E. guerini as two distinct species. Confusingly, Asahina (1977) downgraded masoni as a subspecies of guerini, a decision which was shown to be incorrect by Van Tol & Rozendaal (1995). Asahina (1977) described subspecies Euphaea guerini inouei (= E. masoni inouei) on the basis of ten males and three females from Lam Dong and Dak Lak provinces in southern Vietnam. Earlier Asahina (1969) had mixed the inouei specimens among specimens of the real E. guerini. According to the original description, the subspecies inouei is distinguished from masoni by the black markings on the FW extending less and by the more extensive hyaline part at the apex of the HW compared to Euphaea masoni (see also Asahina 1977). Van Tol & Rozendaal (1995) wrote: “ Whether inouei can be considered a distinct taxon, or only the extreme end of a clinal variation within masoni, should be investigated further. ” Hämäläinen & Karube (2001) also urged the need to study the obvious clinal variation of masoni within its whole range in order to find out if subspecific splitting has a sound basis. Kosterin (2010, 2014) reported individual variation for these characters in Euphaea masoni in south-western Cambodia. The genital ligula and anal appendages of inouei are identical to those of masoni. It should be noted here that recently Hämäläinen (2016: 25, Note 39) listed Euphaea inouei as a good species based on morphological and unpublished molecular evidence. Here we have not attempted to separate our specimens from Vietnam into the taxa masoni and inouei, but list all of them simply as masoni. However, the wing upperside of males from Vietnam (and eastern Cambodia) show a strong iridescent coppery-red flash in sunshine and the HW underside, except for its distal part, shows a slight deep-blue flash. At the same time males from Thailand and south-western Cambodia of the typical Euphaea masoni, described from the border between Myanmar and Thailand, show only a very slight purple shine on the wing upperside and no flash on the wing underside (Kosterin 2014, 2016). These differences indicate the possibility that the Vietnamese populations concern a different taxon from Euphaea masoni sensu stricto. Euphaea masoni resembles E. guerini, E. hirta, and E. saola sp. nov. in body and wing coloration and structure of the anal appendages. However, males of these species can be separated by their abdominal setae tuft patterns visible in lateral view (Fig. 15). In Euphaea masoni, only S 3 has setae (Fig. 15 d), but in other species tufts of setae are present on several other abdominal segments (Fig. 15 a – c). The upper hindwing of Euphaea masoni males shows an iridescent coppery-red flash. In Euphaea hirta this flash is even brighter. By contrast, this flash is green, not red, in E. guerini and E. saola sp. nov. Vesicle of Euphaea masoni (Fig. 18 e) is similar to those of E. guerini (Fig. 18 c) and E. hirta (Fig. 18 d) with its posterior margin rounded. Females of Euphaea masoni can be distinguished from those of E. hirta, E. guerini, and E. saola sp. nov. by wider yellowish stripes on head, thorax, and abdomen (Fig. 16 c), although identification is complicated as a result of different stages of maturity being more or less extensively marked. For additional differences with Euphaea hirta see below under that species.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFFAEC38B594FE01FBCAD55B.taxon	distribution	Distribution. Vietnam (Ha Giang, Cao Bang, Bac Kan, Lang Son, Bac Giang, Lao Cai, Yen Bai, Phu Tho, Vinh Phuc, Ha Tay, Ha Noi, Hoa Binh, Thanh Hoa, Nghe An, Ha Tinh, Quang Ninh, Quang Binh, Quang Tri, Thua Thien-Hue, Da Nang, Quang Nam, Dak Lak, Kon Tum, Gia Lai, Lam Dong, Ninh Thuan, Dong Nai and Tay Ninh Provinces), China (Guangxi and Yunnan Provinces) (Zhang 2010), Laos (Phongsali, Luang Namtha, Oudomxay, Houaphan, Xaignabouli, Vientiane, Bolikhamxay and Attapeu Provinces) (Fraser 1933, Yokoi 1999, Yokoi & Kano 2002, Yokoi & Souphanthong 2004, 2005, this study), Cambodia (Ratanakiri and Mondulkiri Provinces) (Kosterin 2014, 2016), Myanmar (without exact localities; including the holotype from Tenasserim Range, Burma [Selys 1879]), Thailand (most provinces) (Hämäläinen 2017), Malaysia (Perlis state) (Dow et al. 2016), India (Manipur and Nagaland) (Mitra 2002), Bangladesh (Chittagong division) (Khan 2017 b).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFC5EC39B594F9F8FC44D7B3.taxon	materials_examined	Materials examined. [Vietnam] 1 ♂, Bao Loc, Lam Dong Prov., 16. III. 2016, Q. T. Phan leg. (PQTC); 2 ♂, Bao Loc, Lam Dong Prov., 22. IV. 2016, Q. T. Phan leg. (PQTC); 1 ♂, Bao Loc, Lam Dong Prov., 16. V. 2016. T. Kompier leg. (TKC); 1 ♀, Bao Loc, Lam Dong Prov., 12. VI. 2016, T. Kompier leg. (TKC); 2 ♂ 2 ♀, Nam Nung Nature Reserve, Dak Nong Prov., 25. III. 2013, F. Hayashi leg. (FHC); 9 ♂ 2 ♀, Da Ton, Bao Lam District, Lam Dong Prov., 21. IV. 2016, Q. T. Phan leg. (PQTC).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFC5EC39B594F9F8FC44D7B3.taxon	description	Female specimen used for description: 1 ♀, Nam Nung Nature Reserve, Dak Nong Prov., 25. III. 2013, F. Hayashi leg.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFC5EC39B594F9F8FC44D7B3.taxon	materials_examined	Other materials confirmed by field observations. [Vietnam] Some individuals, Lam Dong Prov., V, VI. 2016, V. 2017, T. Kompier; 7 exs, Cat Tien National Park, Dong Nai Prov., 29. I. 2017, T. Kompier. Notes. Euphaea hirta was originally described based on male specimens from Lam Dong Prov., Vietnam (Hämäläinen & Karube 2001), and is characterized by the paraproct being invisible in lateral view (a character unique within the genus) and by the abundant setae on the abdomen (notably on S 4 – 5, S 8 – 10 and cerci) (Fig. 15 c) of the male in comparison to E. guerini (Fig. 15 b) and E. masoni (Fig. 15 d); E. guerini also differs from both hirta and masoni by wholly opaque hind wings (Fig. 14 a – c). The female of Euphaea hirta has not been reported earlier and is described in this paper for the first time. It can be distinguished from female Euphaea masoni by the lateral corners of posterior lobe of prothorax rounded (Fig. 18 i), not angular as in E. masoni (Fig. 18 j). In addition, it has narrow thoracic stripes and reduced abdominal markings compared to Euphaea masoni (Fig. 16 a, c) and its frons lacks yellowish markings (Fig. 16 b). Female of Euphaea hirta resembles female E. guerini and E. saola sp. nov., but these two species have narrower yellowish markings on thorax (Figs 16 d – e), although to some extent these characters are age-dependant and must be treated with care.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFC5EC39B594F9F8FC44D7B3.taxon	description	Description of female. Head (Fig. 16 a – b). Anteclypeus, postclypeus, frons, and all upper parts of head are black, but for two oval yellowish spots between the antennae and the lateral ocelli. Genae and area between clypeus and eye border broadly yellow, with a black oval spot inside. Base of mandibles yellow, but anterior margin black. Labrum, with large yellow spot, split almost in two parts, but connected along ventral border. Antennae black. Thorax (Fig. 16 a). Prothorax is black with a yellow spot on the propleuron. Anterior lobe is entirely black, the middle lobe is black with a pair of large triangular yellow spots. The posterior lobe is black with a small yellow spot at the center and the lateral corners extensively yellow (Fig. 18 i). Synthorax black with yellow stripes along sutures as shown in Fig. 16 a. Legs. Entirely black. Wings. Hyaline with black venation. Abdomen (Fig. 16 a). Black with yellow marking laterally as follows: S 1 has a broad marking. S 2 – 6 have long and thin stripes becoming indistinct distally on each segment. S 7 with small anterolateral spot. S 8 – 10 wholly black. Ovipositor black, shown in Figure 16 a. Measurement (in mm). HW 28; abdomen (incl. appendages) 26.	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
006F87D3FFC5EC39B594F9F8FC44D7B3.taxon	distribution	Distribution. Vietnam (Dak Nong, Lam Dong and Dong Nai Provinces).	en	Phan, Quoc Toan, Kompier, Tom, Karube, Haruki, Hayashi, Fumio (2018): A synopsis of the Euphaeidae (Odonata: Zygoptera) of Vietnam, with descriptions of two new species of Euphaea. Zootaxa 4375 (2): 151-190, DOI: 10.11646/zootaxa.4375.2.1
