Hydrophis trachyceps Theobald, 1868 synonym of Hydrophis cyanocinctus Daudin, 1803 (Table 1; Fig. 1) Material Examined. ZSI 8266 Syntype from Mergui (Beik, Southern Myanmar). Description. Head robust, head shields large, regular; Nasal superior in position, nasal shield in contact with each other; Prefrontal short, 2 nd supralabial touching prefrontal; Frontal longer than the distance from the tip of the rostral; Parietal longer than wide; One large anterior temporal; One Supraocular on each sides of head; One Pre- and Postocular on each side of head; Seven Supralabials on each sides of head; 2 nd touching prefrontal; 3 rd and 4 th touching the eye on the left, 3 rd, 4 th and 5 th touching the eye on the right; 5 th broken; Infralabial 9; 3 infralabials touching chin shield; Chin shield well developed, both the pairs in contact with each other; Anterior Pair 2.5 mm, Posterior Pair 2.5 mm; Scales around neck and midbody, Ventrals and Preanals could not be counted with confidence, as they are in fragile condition due to suboptimal preservation; Head width 9.1 mm; Head depth 11.2 mm; Head length 19.1 mm; Snout to Vent length 860.0 mm; Tail length 78.0 mm. Dorsally and ventrally the entire body brown. Body encircled with dark brown bands, disappearing ventrally. Number of bands 56 around body till vent; Three bands on tail. Remarks. Wall (1906) did not feature this specimen or the nominal taxon either as valid or as a synonym of H. cyanocinctus. Smith (1926) stated it to be a subadult female, with scale rows 31:43 and ventrals “?”. This was so due to the suboptimal preservation of the specimen. Since this was the case even in Smith’s days, we too were unable to score any more characters than those presented. Sclater (1891) listed H. trachyceps under the synonymy of H. cyanocinctus, whereas Boulenger (1890) did not. Also, Sclater (1891) listed two specimens “ZSI 8266-7” as the types of H. trachyceps. Das et al. (1998) clarified that this second syntype ZSI 8267 was not present in the ZSI and that it was not received back from Boden Kloss, probably its collector / their associate in Myanmar or a naturalist who had earlier taken a study loan of that specimen. Boulenger (1896) treated H. trachyceps as a synonym of H. cyanocinctus.

Published as part of Mondal, Sonia, Ganesh, S. R., Sethy, P. G. S., Raghunathan, C., Raha, Sujoy & Sarkar, Sagnik, 2022, Redescriptions of the type specimens of synonymous nominal taxa of sea snakes (Serpentes: Elapidae: Hydrophis, Laticauda) at the Zoological Survey of India, pp. 301-321 in Zootaxa 5169 (4) on page 302, DOI: 10.11646/zootaxa.5169.4.1, http://zenodo.org/record/6952413