THE PRINCIPAL SPECIES OF POISONOUS SNAKES 133 



curved teeth. Saout loag, bearing the nostcils on its upper 

 surface; head-shields large, nasals in contact with each other. 

 Body rather short ; scales hexagonal or squarish, juxtaposed ; no 

 distinct ventral scales. 



The principal species of this genus 

 is H. platurus (syn. Pelamis hicolor, 

 fig. 78). 



Coloration black or brown and 

 yellow, with very variable markings. 



Total length, 700 millimetres ;. tail 

 80. 



Habitat : Indian Ocean, Tropical 

 and Sub-tropical Pacific. 



FtG. 78. — Hi/dr us platurus (syn. 



Pelamis bicolor). 



(After Krefft.) 



(2) Thalassophis. 



Poison-fangs followed by 5 small teeth. Snout short ; nostrils 

 superior, horizontal, between two nasal shields and an inter-nasal ; 

 frontal and parietal shields large ; praeocular present. Body rather 

 elongate ; scales hexagonal, juxtaposed ; no distinct ventral scales. 



T. anomalus. — Body with dark annuli, wider on the back. 



Total length, 810 millimetres ; tail 84. 



Habitat : Java. 



(3) Acalyptophis. 



Maxillaries longer than the ectopterygoids ; frontal and parietal 

 shields broken up into scales. Body rather elongate ; scales sub- 

 imbricate ; no distinct ventrals. 



A.peronii. — Greyish or pale olive, with dark cross-bands ; belly 

 whitish. 



Total length, 890 millimetres ; tail 115. 



Habitat : Western Tropical Pacific. 



