Stegonotus keyensis ( Doria, 1874:351 ) Kaiser & Kaiser & O’Shea, 2018

Kaiser, Christine M., Kaiser, Hinrich & O’Shea, Mark, 2018, The taxonomic history of Indo-Papuan groundsnakes, genus Stegonotus Duméril et al., 1854 (Colubridae), with some taxonomic revisions and the designation of a neotype for S. parvus (Meyer, 1874), Zootaxa 4512 (1), pp. 1-73 : 35-36

Stegonotus keyensis ( Doria, 1874:351) n. comb.

Taxonomic status. Lycodon keyensis has heretofore been considered as a synonym of S. cucullatus . Based on lower ventral and subcaudal counts, a much shorter tail relative to overall body size as indicated by SCR values, and a distance of over 500 km from the type locality of S. cucullatus across the Bird’s Head Peninsula of West Papua and the Seram Sea, we hereby remove this species from the synonymy of S. cucullatus . The Kei Island populations of Stegonotus therefore take the name Stegonotus keyensis n. comb.

Synonyms. None.

Original name. Lycodon keyensis Doria, 1874:351 . The species was described by Giacomo Doria (see above), who presented the description in Italian. It is named for the Kei Islands, its geographic origin.

Holotype. MSNG 7521 ( Fig. 19 ; Table 1), most likely an adult male (see below).

Type locality. “Isole Kei” [the Kei Islands, Maluku Province, Indonesia]. Just as in the case of the Aru Islands, the locality “Isole Kei” is not specific enough to determine on which of the Kei Islands the specimen was collected. A description of Beccari’s visit to these islands, supported by Beccari’s own cited letters to Doria (Gigliolo 1874), shows that Beccari spent most of his time on Dullah and Kei Kecil, after having been shipwrecked on the voyage from Aru on Kei Besar ( Anonymous 2018a). It is therefore not possible to restrict the type locality further.

Collector. The specimen was collected by Odoardo Beccari (see above), who arrived in the Kei Islands on 6 July 1872 and departed from the main town of Tual on Dullah for Ambon on 4 September 1872. It was therefore collected between those dates.

Key characteristics of the holotype. O (651) mm SVL + 170 (164) mm TL = 800 (815) mm TTL. V ♂ = 200 (200), SC ♂ = 73 (73), SCR ♂ = O (0.27), D = O-17-O (17-17-15), SL E = 4+5 (4+5), SL = 9 (9), IL = O (9L 10R), IL G = O (5). Based on the SC count of 73 and then non-overlapping sexual dimorphism in SC numbers (see below), we believe this specimen to be a male and treat it as such.

Key characteristics of the species. We were able to examine seven specimens of S. keyensis that were collected on one of the Kei Islands. Of these, two females were collected on Dullah, two males on Kei Besar, one male on Taam, and two (1 ♀, 1 ♂), including the male holotype, were collected at unspecified localities. Characteristics include V ♀ = 188–200 (193 ± 6.1), V ♂ = 200–207 (204 ± 3.5); SC ♀ = 59–66 (63 ± 3.5), SC ♂ = 70–80 (74 ± 5.1); SCR ♀ = 0.25, SCR ♂ = 0.27; D = 17-17-15 (100%); SL E = 4+5 (n = 6, 86%) or 3+4 (n = 1, 14%); SL = 8 (n = 5, 71%) or 9 (n = 2, 29%); IL = 8 (n = 2, 29%), 9 (n = 3, 43%), or 10 (n = 2, 29%); IL G = 5. The species shows sexual dimorphism with respect to the numbers of both ventral and subcaudal scales. This difference does not result in obviously different SCR values, but this may be a statistical artifact of comparing ratios when sample sizes are small. Roux (1910) reported on two specimens (no numbers provided), one from Dullah and the other from Kei Besar. Both of these fit within the parameters for S. keyensis , as reported above.

Comments. The set of infralabial scales on the right side of the holotype presents one unusual feature, a fragmentation of IL9 into two small, shallow scales, each of which we counted to arrive at our count of IL = 10 L. Boulenger (1893) synonymized the species with S. cucullatus , but Roux (1910) considered it more likely that the synonymy should be with S. modestus . We have found no evidence for the occurrence of either S. cucullatus or S. modestus in the Kei Islands. The existence of the species has so far only been confirmed for Dullah and Kei Besar using voucher specimens, but it is likely that it occurs on other nearby islands as well.

Figures

FIGURE 19. Holotype of Stegonotus keyensis (Doria, 1874) new combination, MSNG 7521, an adult male from the Kei Islands, Maluku Province, Indonesia. Shown are the entire specimen (TTL = 815 mm) in (A) dorsal and (B) ventral views, and its head in (C) dorsal, (D) right lateral, and (E) ventral views.