Diplocephalus circularis Irfan, Zhang & Peng

Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, Megataxa 15 (1), pp. 1-248 : 43-46

Diplocephalus circularis Irfan, Zhang & Peng , sp. n.

(vä双头e)

Figures 53–57 , 307 , 312 , 315

Types. Holotype ♂, CHINA, Hubei Prov.: Badong Co., Yanduhe Town, Songziyuan Vill. , 31.35278°N, 110.39937°E, 1836 m, 27.IV.2016, W. Liu et al. leg . Paratypes: 16♂ 13♀, with same data as for holotype; 6♂ 9♀, Badong Co., Yanduhe Town, Songziyuan Vill. , 31.33400°N, 110.42625°E, 1340 m, 28.IV.2016, W. Liu et al. leg.; 1♂, Badong Co., Yanduhe Town, Songziyuan Vill. , 31.3406°N, 110.4131°E, 1320 m, 24.IV.2016, W. Liu et al. leg.; 5♀, Enshi Co., Xingdou MNNR , 30.04166°N, 109.13377°E, 1253 m, 18.V.2017, G.C. Zhou et al. ( HNU–HB– IV–1710 ); Hunan Prov.: 1♂, Shaoyang City, Suining Co., Zhaishi Town , Tieshanlin Vill. , Huangshan NNR , 26.37646°N, 110.10573°E, 1129 m, 26.X.2017, G.C. Zhou ( HNU–HN– IV–1759 ); Chongqing: 1♀, Youyang Co., Taohuayuan Scenic Spot , 28.85096°N, 108.75037°E, 995 m, 23.VII.2017, M. Irfan & G.C. Zhou ( HNU–CQ– IV–1718 ).

Etymology. The specific epithet is derived from the Latin adjective “circularis ” meaning “circular” and referring to the curved anterior terminal apophysis in male palp.

Diagnosis. The male of Diplocephalus circularis sp. n. resembles that of D. crassilobus in having the similar cephalic lobe in male ( Figs 57A–C ; Millidge 1979, figs 50–56), but can be distinguished by the embolus forming a complete 360° circle in D. circularis sp. n. ( Figs 53A– C , 54A, B , 55A–C ; vs. spindle-shaped); dorsal tibial apophysis at apex ventrally with two projections in D. circularis sp. n. ( Figs 54C, D ; vs. with one projection). The female of D. circularis sp. n. resembles those of D. parentalis in having similar ventral plate and fissure in epigyne ( Figs 56A–D ; Song and Li, 2010, figs 10G, 11A, B), and can be distinguished by the spermathecae Ushaped, pointing towards the anterior margin of epigyne in D. circularis sp. n. ( Figs 56B, D ; vs. J-shaped, pointing towards the posterior margin of epigyne).

Description. Male (holotype, Figs 57A–C ): Total length: 1.53. Carapace 0.71 long, 0.57 wide, cephalic region with cephalic lobe 0.27 high, yellow, fovea, cervical and radial grooves distinct. Clypeus 0.24 high. Chelicerae with three promarginal and four retromarginal teeth. Sternum longer than wide, yellowish with microsetae. Eye PMEs presents on the cephalic lobe, AER recurved, PER procurved. Eye sizes and interdistances: AME 0.05, ALE 0.04, PME 0.05, PLE 0.04, AME–AME 0.01, PME–PME 0.08, AME–ALE, 0.06, PME–PLE 0.12, AME–PME 0.12, ALE–ALE 0.28, PLE–PLE 0.27, ALE–PLE 0.01. Length of legs: I 1.9 (0.55, 0.64, 0.42, 0.29), II 1.75 (0.53, 0.56, 0.39, 0.27), III 1.54 (0.46, 0.48, 0.34, 0.26), IV 1.96 (0.36, 0.63, 0.44, 0.26). Tibial spine formula: 2-2-1-1. TmI 0.19 and TmIV absent. Opisthosoma 0.99 long, 0.72 wide, oval, dark brown to black.

Palp (holotype, Figs 53A–D , one of the paratype, Figs 54A–D ): Femur unmodified, as long as patella and tibia. Patella shorter than tibia, ventrally grooved. Tibia dorsally with broad, long dorsal tibial apophysis, retrolateral margin with a row of thick setae, apex with two projections extending retrolaterally with teeth. Cymbium unmodified, conical, distal end broad; paracymbium (PC) L-shaped, distal arm tip hook-shaped with blunt end; tegulum (T) with well developed protegulum (PT), protruding above the apex of cymbium; distal suprategular apophysis (DSA) sclerotized, basal part broad, distal end needle-like with pointed end. Tailpiece (TP) of embolic division long, curved with blunt tip; embolic membrane (EM) long, with broad end; embolus (E) long, highly sclerotized, forming a tranvers circular at the apex.

Variation (one of the paratype palp, Figs 55A–D ): Distal long arm of distal suprategular apophysis with a tooth. All the other morphological and genital characters are similar to the male holotype.

Female (paratype, Figs 57D–F ): Total length: 1.56. Carapace 0.66 long, 0.55 wide, cephalic region slightly elevated, yellow, fovea, cervical and radial grooves distinct. Clypeus 0.14 high. Chelicerae with 4 promarginal and 6 retromarginal teeth. Sternum longer than wide, yellowish with microsetae. Eyes: AER recurved, PER procurved. Eye sizes and interdistances: AME 0.03, ALE 0.04, PME 0.04, PLE 0.04, AME–AME 0.02, PME–PME 0.04, AME–ALE, 0.04, PME–PLE 0.03, AME–PME 0.05, ALE–ALE 0.22, PLE–PLE 0.23, ALE–PLE 0.01. Length of legs: I 1.75 (0.54, 0.59, 0.33, 0.29), II 1.68 (0.50, 0.54, 0.34, 0.30), III 1.37 (0.46, 0.40, 0.27, 0.24), IV 1.77 (0.57, 0.61, 0.35, 0.24). Tibial spine formula: 2-2- 1-1. TmI 0.17 and TmIV absent. Opisthosoma 1.14 long, 0.78 wide, oval, dark brown to black.

Epigyne ( Figs 56A–D ): Epigynal plate more than two times wider than long, medially with a long fissure (F); ventral plate (VP) with copulatory openings (CO) anteriorly; dorsal plate (DP) somewhat quadrate, postrior end round, completly covered by ventral plate in ventral view; copulatory ducts (CD) enclosed in a slightly sclerotized capsule. Spermathecae (S) present anterolaterally, spaced by two diameters. Fertilization ducts (FD) present dorso mesally.

Distribution. Known only from the type localities (Chongqing, Hubei and Hunan Provinces, Figs 307 , 312 , 315 ).

Figures

FIGURE 53. Diplocephalus circularis sp. n., male holotype. A Palp, prolateral view; B Palp, retrolateral view; C Palp, ventral view; D Palp, dorsal view. Abbreviations: DSA—distal suprategular apophysis; E—embolus; EM—embolic membrane; PC— paracymbium; PT—protegulum; PTA—prolateral tibial apophysis; RBP—cymbial retrobasal process; SPT—suprategulum; ST— subtegulum; T—tegulum; TP—tailpiece.

FIGURE 54. Diplocephalus circularis sp. n., male palp (one of paratype). A Embolic division, prolateral view; B Embolic division, posterior view; C Tibia, dorsal view; D Tibia, ventral view. Abbreviations: DSA—distal suprategular apophysis; E—embolus; EM—embolic membrane.

FIGURE 55. Diplocephalus circularis sp. n. male paratype. A Palp, prolateral view; B Palp, retrolateral view; C Palp, ventral view; D Palp, dorsal view. B, C Red arrows indicating distal long arm of distal suprategular apophysis with a tooth.Abbreviations:DSA— distal suprategular apophysis; E—embolus; EM—embolic membrane; PC—paracymbium; PT—protegulum; PTA—prolateral tibial apophysis; RBP—cymbial retrobasal process; SPT—suprategulum; ST—subtegulum; T—tegulum; TP—tailpiece.

FIGURE 56. Diplocephalus circularis sp. n., female (one of paratype). A, B Epigyne, ventral view; C, D Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP— ventral plate.

FIGURE 57. Diplocephalus circularis sp. n., male holotype (A–C), female (one of paratypes, D–F). A, D Habitus, dorsal view; B, E Habitus, lateral view; C, F Habitus, ventral view.

FIGURE 307. Distribution of Linyphiidae species in Chongqing: 1. Bathyphantes paracymbialis Tanasevitch, 2014; 2. Diplocephalus circularis sp. n.; 3. Frontinella zhui Li & Song, 1993; 4. Gnathonarium dentatum (Wider, 1834); 5. Gongylidioides acuminatus sp. n.; 6. Gongylidioides ensis sp. n.; 7. Gongylidium uncatum sp. n.; 8. Himalaphantes azumiensis (Oi, 1979); 9. Hylyphantes graminicola (Sundevall, 1830); 10. Indophantes wushanensis Irfan, Wang & Zhang, 2023; 11. Lepthyphantes frondeus sp. n.; 12. Wulinggone qizimeiensis sp. n.; 13. Nematogmus ligulatus sp. n.; 14. Nematogmus sanguinolentus (Walckenaer, 1841); 15. Nippononeta alpina (Li & Zhu, 1993); 16. Nippononeta coreana (Paik, 1991); 17. Oia yinae sp. n.; 18. Oilinyphia xinqiaoensis sp. n.; 19. Oilinyphioides triangularis sp. n.; 20. Prosoponoides sinensis (Chen, 1991); 21. Scotinotylus guizhouensis sp. n.; 22. Sinolinyphia henanensis (Hu, Wang & Wang, 1991); 23. Syedra yuelushanensis sp. n.; 24. Ummeliata feminea (Bösenberg & Strand, 1906); 25. Ummeliata insecticeps (Bösenberg & Strand, 1906); 26. Walckenaeria sinuosa sp. n.; 27. Wuliphantes tongluensis (Chen & Song, 1988).

FIGURE 312. Distribution of Linyphiidae species in Hubei Prov.: 2. Asiagone xingdouensis sp. n.; 3. Bathyphantes paracymbialis Tanasevitch, 2014; 4. Bifurcia cochlearis sp. n.; 5. Capsulia tianmushana (Chen & Song, 1987); 6. Dicristatus cordatus sp. n.; 7. Diplocephalus circularis sp. n.; 8. Erigone prominens Bösenberg & Strand, 1906; 9. Frontinella zhui Li & Song, 1993; 10. Gnathonarium dentatum (Wider, 1834); 11. Gongylidioides ensis sp. n.; 12. Gongylidioides microdontus sp. n.; 13. Gongylidium dawolongense sp. n.; 14. Gongylidium minutum sp. n.; 15. Gongylidium uncatum sp. n.; 16. Houshenzinus rimosus Tanasevitch, 2006; 17. Hylyphantes graminicola (Sundevall, 1830); 18. Indophantes wushanensis Irfan, Wang & Zhang, 2023; 1. Microneta maliuxiensis sp. n..

FIGURE 315. Distribution of Linyphiidae species in Hunan Prov.: 1. Acanoides cornutus sp. n.; 2. Acanoides ningxiangensis sp. n.; 4. Auriculaiana yongshunensis sp. n.; 5. Baryphyma xiaoxiense sp. n.; 6. Bathyphantes paracymbialis Tanasevitch, 2014; 7. Bathyphantes pseudogracilis sp. n.; 8. Bifurcia ramosa (Li & Zhu, 1987); 9. Bolyphantes arcuatus sp. n; 10. Bolyphantes gladius sp. n.; 11. Capsulia tianmushana (Chen & Song, 1987); 12. Dicristatus cordatus sp. n.; 13. Diplocephalus circularis sp. n.; 14. Drapetisca boletus sp. n.; 15. Drapetisca nanpingensis sp. n.; 16. Drapetisca yuelushanensis sp. n.; 17. Erigone prominens Bösenberg & Strand, 1906; 18. Frontinella zhui Li & Song, 1993; 19. Gnathonarium dentatum (Wider, 1834); 20. Gnathonarium gibberum Oi, 1960; 21. Oedothorax fortis sp. n.; 22. Tapinocyba sulcata sp. n.; 23. Himalaphantes azumiensis (Oi, 1979); 24. Hylyphantes graminicola (Sundevall, 1830); 25. Kaestneria bicultrata Chen & Yin, 2000; 26. Lepthyphantes frondeus sp. n.; 27. Microlinyphia zhejiangensis (Chen, 1991); 3. Microneta acutalis sp. n.; 28. Nematogmus sanguinolentus (Walckenaer, 1841); 29. Nippononeta alpina (Li & Zhu, 1993); 30. Nippononeta coreana (Paik, 1991); 31. Oia baiyunensis sp. n.; 32. Oia lata sp. n.; 33. Oia yinae sp. n.; 34. Oilinyphioides triangularis sp. n.; 35. Paikiniana lurida (Seo, 1991); 36. Parameioneta bilobata Li & Zhu, 1993; 37. Prosoponoides sinensis (Chen, 1991); 38. Ryojius lianghekouensis sp. n.; 39. Ryojius nanyuensis (Chen & Yin, 2000); 40. Scotinotylus longiprojectus sp. n.; 41. Shaanxinus insectus sp. n.; 42. Shaanxinus longiembolus sp. n.; 43. Sinolinyphia henanensis (Hu, Wang & Wang, 1991); 44. Syedra yuelushanensis sp. n.; 45. Tenuiphantes taipingensis sp. n.; 46. Ummeliata feminea (Bösenberg & Strand, 1906); 47. Ummeliata insecticeps (Bösenberg & Strand, 1906); 48. Walckenaeria xingdouensis sp. n.; 49. Walckenaeria extenuata sp. n.; 50. Walckenaeria yanglinensis sp. n.; 51. Wuliphantes tongluensis (Chen & Song, 1988); 52. Yuelushannus diaotangensis sp. n.; 53. Yuelushannus jinyuanensis sp. n.; 54. Yuelushannus wenfengensis sp. n..