Homalopsis hardwickii Gray, 1842

Murphy, John C., Voris, Harold K., Traub, Joshua & Cumberbatch, Christina, 2012, The masked water snakes of the genus Homalopsis Kuhl & van Hasselt, 1822 (Squamata, Serpentes, Homalopsidae), with the description of a new species, Zootaxa 3208, pp. 1-26 : 12-13

Homalopsis hardwickii Gray, 1842

Fig. 1 b

Homalopsis buccata— Günther 1864:285; Boulenger 1890: 374; 1896: 14; Smith 1943: 390. Wall 1903: 94; Wall 1923: 38; Gyi 1970: 136; Murphy 2007: 193

Type locality. “ India.”

Holotype. BMNH 1946.1.7.26.”

Distribution. Possibly restricted to northeast India, no known extant population. The holotype of Homalopsis hardwickii is reported to be from India, but the datum is questionable. Two other specimens (BMNH 111.18.1 b, g) that may be H. hardwickii have the locality of “Bengal” but do not agree well with the holotype and the locality information is followed by a question mark in the BMNH catalog. Thus, this species remains to be re-discovered and its distribution to be determined.

Diagnosis. Homalopsis hardwickii has a divided loreal contacting upper labials 1–4; two prefrontal scales; 39 scale rows at midbody reduced to 28 posteriorly; one postocular scale and no presubocular scale; 13 or 14 upper labials; 159 ventrals. Homalopsis buccata has a single loreal contacting upper labials 1–4; one postocular scale plus a postsubocular scale; H. nigroventralis has upper labials 1–3 contacting the loreal; one or two postocular scales plus one postsubocular scale; and a reverse color pattern on the venter (dark olive-gray with white spots). H. semizonata has three prefrontals; one postocular and one postsubocular. The new species, H. mereljcoxi , has a single loreal contacting upper labials 1–4; 40–49 scale rows at midbody, reduced to 30 or more posteriorly; and two postocular scales plus a postsubocular.

Redescription of the Holotype. A male, 511 mm SVL, 172 mm tail; dorsal scale rows 41–39–28; 159 ventrals; 84 subcaudals; 1/1preocular, 1/1 postocular, 1/1 postsubocular, no subocular; internasal small and divided; 2/ 2 prefrontals; temporal formula 1/1; upper labials 14/13, first six not horizontally divided; upper labials under orbit 5/6; upper labials in contact with loreal 1-4/1-4; loreal divided on both sides. It has a typical Homalopsis pattern with alternating dark brown separated by white saddle-like blotches, the light blotches number 44, of which 19 do not extend to the vertebral line.

Material examined. “ INDIA ” BMNH 1946.1.7.26 (type).

Figures

FIGURE 1. Ocular ring morphology in five species of Homalopsis. Scale nomenclature: 1 = preocular, 2 = presubocular, 3 = subocular, 4 = postsubocular, 5 = postocular. A. H. buccata: preocular (s) one or two, presubocular one, subocular (s) present about 50 % of the time, postocular (s) one or two, postsubocular one (but may be absent). B. H. hardwickii has the lowest number of scales in the ocular ring of any specimen (or species) examined: preocular one, presubocular not present, subocular not present (upper labial in orbit), postocular one, postsubocular one. C. H. mereljcoxi: preocular one, presubocular one (but may be absent), suboculars two or three (rarely absent or four), upper labial six rarely present in orbit, postoculars two (rarely one), postsubocular one (rarely absent). D. H. nigroventralis has the largest number of scales in the ocular ring: preocular one, presubocular one, suboculars one or two (rarely three), postoculars two or three, postsubocular one. E. H. semizonata has the most consistent number of scales in the ocular ring: preocular one (rarely two), presubocular one, subocular one (rarely does a lower labial enter the orbit as it does in the photo), postocular one, postsubocular one.