Leptopelis bocagii (Günther, 1865)

Parrinha, Diogo, Calado, Francisco M. G., Marques, Mariana P., Bauer, Aaron M. & Ceríaco, Luis M. P., 2025, Echoes of a lost museum: Revision of the herpetological collections sent by Barbosa du Bocage from the Lisbon Museum to the British Museum of Natural History, Vertebrate Zoology 75, pp. 353-404 : 353-404

Leptopelis bocagii (Günther, 1865) *

Specimens.

Angola: “West Africa” [= Duque de Bragança ]: BMNH 1875.5.22.3 (Fig. 6 ), BMNH 1875.5.22.2 [ holotype; Figs 7 , 8 ] , Quissange : BMNH 1887.3.23.3 , Caconda : BMNH 1887.3.23.2 (not examined) [ syntype of Hylambates angolensis Bocage, 1893 ], “ Angola ”: BMNH 1896.2.28.2 (not examined).

Comments.

Cystignathus bocagii was described by Günther (1865 a), but the type material for the taxon is the subject of some confusion ( Bocage 1866 a, 1895 a; Perret 1976; Marques et al. 2018; Frost 2024). In a letter dated 19 September 1864 ( AHMB /CE/G75 ), Günther thanked Bocage for a shipment of reptiles from Duque de Bragança, noting that “ several of the frogs appear to be new ”. Günther stated that “ I shall return all the specimens which you desire to keep, hoping that if you should receive duplicates at some future time, you will kindly communicate to us what you can spare ”. In the original description Günther (1865 a) acknowledged Bocage, “ who has allowed me to examine the unique specimen brought from the province of Duque de Bragança ( Angola) to the Lisbon Museum ”. In a subsequent letter dated 24 July 1865 ( AHMB /CE/G76 ) Günther classified the material sent earlier by Bocage, and although some specimens are noted as having been presented to the British Museum, the holotype of Cystignathus bocagii (identified as No. 11) is listed among the material to be returned to Lisbon ( AHMB /CE/G76 , NHMA /DF/GüntherColl/16/1/104 ; Fig. 5 ). In the following year, Bocage wrote back to Günther expressing doubts concerning the identity of two specimens returned by Günther as Cystignathus bocagii (No. 11, the holotype) and Leptopelis natalensis (No. 12), which were then sent back to London to be reexamined ( AHMB /CE/G78 , NHMA /DF/ZOO/200/1/184 , NHMA /DF/GüntherColl/16/1/110 ). After reexamining the two specimens, Günther agreed with Bocage and confirmed that they both represented Cystignathus bocagii , asking to keep one as duplicate in the British Museum ( AHMB / CE / G / 79). In response, in a letter dated 10 July 1866, Bocage allowed Günther to keep one of the specimens but wished to keep the type in Lisbon ( NHMA /DF/ZOO/200/1/185 ).

In the first issue of the Jornal de Sciencias Mathematicas, Physicas e Naturaes, published in November of the same year, Bocage (1866 a) mentioned two specimens collected by Bayão from Duque de Bragança, stating that “ Um d’elles é o typo da especie, o outro offerecemol-o ao Museu Britannico ” [One of them is the type of the species, the other we offered to the British Museum]. Years later, in his Catalogue of the Batrachia Salientia in the British Museum, Boulenger (1882 b) mentioned two specimens from “ W. Africa ”, originally from the Lisbon Museum (Figs 6 , 7 ). In his major work on Angolan herpetofauna, Bocage (1895 a) stated “ Deux individus, types de l’espèce, qui existent au Muséum Britannique et deux autres individus jeunes faisant partie de nos collections d’Angola sont les seuls exemplaires connus de cette espèce ” [ two specimens, types of the species, that exist in the British Museum and two other juvenile specimens that are part of our collections from Angola are the only known exemplars of this species]. When Perret (1976) examined the types in the Lisbon Museum he referred to a juvenile from Duque de Bragança as “ Cotype I ” ( MB T.15 -232), and Frost (2024) stated that two specimens sent to the British Museum may be types.

We are confident that one of the two specimens from “ West Africa ” ( BMNH 1875.5.22.2 –3; Figs 6 , 7 ) cited by Boulenger (1882 b) corresponds to the holotype of Cystignathus bocagii . These specimens are accessioned in the register as Hylambates bocagei from “ W. Africa ” with a note stating they were “ Received some years ago from the Lisbon Museum for examination ”, suggesting that they were those initially sent in Bocage’s first shipment of specimens from Duque de Bragança and later sent again for reexamination ( AHMB /CE/G76 , NHMA /DF/GüntherColl/16/1/104 , 110). While the type was supposed to be returned to Lisbon, we found no additional references that may explain why these specimens remained in London until they were accessioned in 1875. We speculate that Bocage received additional specimens in the meanwhile, leading him to present the specimens to Günther and mention two types in the British Museum ( Bocage 1895 a). The specimens in question were subsequently labeled as Leptopelis viridis , presumably by Parker (1936), who recognized this as the only taxon occurring in West Africa and was unaware of the true origin of the specimens labeled as “ W. Africa ”. Although the specimens still bear the original paper labels where the numbers mentioned in the letters would have been stated, these are completely faded and thus do not allow us to unambiguously match them with those cited in the letters. However, while both specimens generally fit Günther’s (1865 a) description of Cystignathus bocagii , one of them more closely resembles the illustration of the holotype provided by Günther (1865 a) even after 160 years of preservation (Fig. 8 ). The visible discrepancy between the specimen and Günther’s (1865 a) figure is likely a result of the technique used to produce the illustration, resulting in a mirrored image of the specimen ( Ceríaco and Bauer 2017). Furthermore, distinct pectoral glands are evident in BMNH 1875.5.22.3 , a character not mentioned in the original description (Fig. 6 ). Based on this evidence, we recognize BMNH 1875.5.22.2 as the holotype of Leptopelis bocagii .

On 19 March 1887 Bocage sent additional Hylambates material to the British Museum ( NHMA /DF/ZOO/235/1/1/1/76 ), including a specimen of Hylambates anchietae from Caconda (No. 1, see previous account), one specimen from Portuguese Guinea (No. 4, see Leptopelis viridis account) and two other specimens of a species that Bocage considered new: “ 2. Un individu d’une autre espèce de Hylambates , que je n’ai pu rapporter à aucune des espèces décrits dans votre Catalogue et que j’ai nommé provisoirement – H. angolensis , il vient de Caconda ”, “ 3. Un autre individu, provenant d’un autre localité, qui me semble constituer à peine une variété interessante de l’ espèce précedente. Tous les individus que j’ai reçu de cette localité (Quissange) portent la grande tache noire sur les dos ”. Some years later, Bocage (1893 a) formally described Hylambates angolensis , and although he provided measurements for only an adult female, he mentioned material collected by Anchieta from “ Caconda, (…) Quissange, Quibula, Quindumbo et Cahata, dans l’intérieur de Benguella ”. Boulenger (1906 “ 1905 ”) referred Bocage’s Hylambates angolensis to the synonymy of bocagii , mentioning specimens sent by Bocage under that name, and was followed by subsequent authors ( Parker 1936; Perret 1976).

The specimens sent by Bocage in 1887 were accessioned in the British Museum in the same order as listed in the letter, with the numbers BMNH 1887.3.23.1 –4, where BMNH 1887.3.23.2 and 1887.3.23.3 are marked as types of Hylambates angolensis . Of these two putative types, we could only locate BMNH 1887.3.23.3 during our visits. Although the specimen bears the number “ 4 ” on the original label, the remaining data agree with Bocage’s description of No. 3 in the letter, i. e., “ Hylambates angolensis var.? ” from “ Quissange ( Angola) ”. However, it is unclear if the number was originally written by Bocage or subsequently added to the specimen label. Perret (1976) identified three syntypes of Hylambates angolensis in Lisbon: MB T.14 -244 from Quissange, MB. T.14-242 from Caconda and MB T.14 -242 from Quindumbo. While the specimens in the British Museum were presented some years before the formal description was published, the contents of Bocage’s letter ( NHMA /DF/ZOO/235/1/1/1/76 ) suggest that these were already included in his concept of Hylambates angolensis at the time. Although Bocage reconsidered the status of his specimens from Quissange and assigned them to Hylambates angolensis in the published description ( Bocage 1893 a, 1895 a), the fact that he referred to specimen No. 3 ( BMNH 1887.3.23.3 ) in his letter as a variety of his new taxon leads us to follow a conservative definition and not consider this specimen as part of the type series.

An additional specimen of Hylambates angolensis is mentioned in a letter dated 24 February 1896 ( NHMA /DF/ZOO/235/1/1/1/76 ) and listed in the register with the number BMNH 1896.2.28.2 but could not be located. Neither the syntype of Hylambates angolensis ( BMNH 1887.3.23.2 ) nor the last Hylambates specimen shipped from Lisbon ( BMNH 1896.2.28.2 ) are recorded in the British Museum’s modern database and thus remain unaccounted for.

Figures

Figure 5. Extract from letter written by Günther on 25 July 1865 (AHMB / CE / G 76), listing the specimens sent by Bocage for determination, noting first 10 specimens as “ kindly presented to the B. M. ”.

Figure 6. Specimen of Leptopelis bocagii mentioned in the 1866 letter (BMNH 1875.5. 22.3), note presence of distinct pectoral glands. Photos by DP.

Figure 7. Holotype of Leptopelis bocagii (BMNH 1875.5. 22.2). Photos by DP.

Figure 8. Preserved holotype of Leptopelis bocagii (left, BMNH 1875.5. 22.2) and portion of Plate XXXIII adapted from Günther (1865 a) depicting the same specimen (right). Plates often depict a mirrored image of the original illustration, thus the difference between the specimen and the plate.