Boiga barnesii ( Günther, 1869 )

Ganesh, S. R., Achyuthan, N. S., Chandramouli, S. R. & Vogel, Gernot, 2020, Taxonomic revision of the Boiga ceylonensis group (Serpentes: Colubridae): reexamination of type specimens, redefinition of nominate taxa and an updated key, Zootaxa 4779 (3), pp. 301-332 : 310

Boiga barnesii ( Günther, 1869)

( Tables 3–4; Fig. 5 , 9E )

Dipsas barnesii Günther, 1869

Dipsadomorphus barnesii — Boulenger 1896; Wall 1921

Boiga barnesi — Smith 1943; Samarawickrama et al. 2005

Boiga barnesii — Das & De Silva 2005; Somaweera 2006

Specimens examined. Males (n=2). Holotype (by monotypy): Sri Lanka. BMNH 69.7 .24.11, a male from Ceylon.

Other specimen: NMW 25360, a male also from Ceylon .

Etymology. Patronym named after Richard Hawkswoth Barnes who collected the holotype in Ceylon.

Diagnosis. A species of Boiga endemic to Sri Lanka, having 19 midbody scale rows (vs. 21–23 in B. nuchalis , B. dightoni , B. andamanensis ); preoculars 3 on each side of head (vs. preocular 1 in all South Asian congeners); 3 rd supraocular not touching the eye (vs. touching the eye in all other South Asian congeners); vertebral scale row feebly enlarged (vs. strongly enlarged in B. andamanensis , B. ceylonensis , B. beddomei , B. thackerayi ); series of large oblong blotched pattern dorsally (vs. cross bars dorsally in B. ceylonensis ); ventrolateral region with distinct white and black adjacent blotches (vs. such pattern absent in all South Asian congeners except B. thackerayi ).

Redescription of the holotype. A small-sized snake reaching 572 mm total length, with slender habitus, thin neck, wide head; long tail (relative tail length 22.6%); 19–19–14 dorsal scale rows; rostral visible from above; preoculars 3 on each side of head; postoculars 2; loreal 1; supralabials 8, with 4 th, 5 th touching eye; infralabials 10/9, with 1–4 touching chin shields; temporals 10; preventral 2; ventrals 217, angulate laterally; cloacal 1; subcaudals 96 pairs. Dorsum dark greyish-brown, with 47 (32 on body, 15 on tail) blackish-brown, oblong blotches; interspaces often with sparse dark dots; a large dark wash covering the entire top aspect of head from rostrum to occiput; very broad postocular stripe up to jaw angle; labials, chin and venter ashy white, getting darker posteriorly; underside finely spotted with darker hue; venter edged along both sides with a series of large adjacent white and black blotches, alternating at an interval of every 3–4 ventrals.

Variation. Other specimens agreeing with holotype in most aspects; our second male examined show the following variation: snout to vent length 444 mm; tail length 123 mm; relative tail length 22.9%; posterior scale rows 13; temporals 19; ventrals 218; subcaudals 100 pairs; number of cross bars 66 on body.

Distribution and natural history. This species is endemic to Sri Lanka ( Das & De Silva 2005) (Fig. 13). It is restricted to the wet forest zones in the hilly, central and southwestern provinces of the island ( Somaweera 2006). Definite records of this species are from near Kandy ( Samarawickrama et al. 2005).

Figures

FIGURE 5. Holotype of Boiga barnesii BMNH 69.7.24.11a from Ceylon. (A) entire—dorsal, (B) entire—ventral, (C) ventral pattern close-up, (D) head—ventral, (E) head—lateral, (F) head—dorsal views.

FIGURE 9. (A&B) Boiga ceylonensis from Kanneliya & Hunasgiriya, Sri Lanka; (C) Boiga beddomei from Pune, India; (D) Boiga nuchalis from Anaimalai, India; (E) Boiga barnesii from Kandy, Sri Lanka; (F) Boiga andamanensis from Andaman Islands, India.