Black-headed rhynchocalamus

Description

The black-headed ground snake is a small,burrowing snake with a slender body reaching just 36–40 cm (14–16 in) in total length (body + tail).Its smooth and shiny dorsal scales and almost transparent covering make many of its internal organs quite visible,when observed against a light source.The eyes are small,with black irises.The head is covered with symmetrical large shields.The rostral shield is somewhat enlarged and specialized for digging through soil.The dorsal coloration may vary from tan to orange,with no obvious pattern except on the neck and head.The belly is clear white.The pattern on the neck and head is different in the two subspecies.In the nominate subspecies,Rhynchocalamus melanocephalus melanocephalus,there is no separation between the neck pattern and the head pattern.The upper surface of the head and neck is ash-black.Only the labials,the nasals,and the rostal are white.In R.melanocephalus satunini the neck carries a black semi-collar,and the head pattern consists of three transverse black saddles.The first one is on the rostral.The second spreads over the postnasal,supraorbital,and frontal,and partially over the prefrontal shields from eye to eye.The third saddle covers the parietal shields and some of the surrounding scales.The spaces between the black saddles are white,which makes Rhynchocalamus visually identifiable from similar looking species of the genera Eirenis and Pseudocyclophis,which often occupy the same habitat.