THE PRINCIPAL SPECIES OF POISONOUS SNAKES 135 
H. spiralis.—Olive above, yellowish beneath, with black rings ; 
head black above, with a horse-shoe-shaped yellow mark, the 
convexity of which rests on the prefrontal shields; end of tail 
black. 
Total length, 400 millimetres. Grows to 1,800 millimetres. 
Habitat : Coasts of India, and the Malay Archipelago. 
H. cærulescens.—Grey above, with black cross-bands, which 
form complete rings, or are interrupted on the belly ; head uniform 
black. | 
Total length, 665 millimetres ; tail 75. 
Habitat: Bombay Coast, Bay of Bengal, Straits of Malacca. 
H. nigrocinctus.—Pale olive on the back, yellowish on the belly, 
with black annuli, which are broader on the back. 
Total length, 1,000 millimetres ; tail 100. 
Habitat: Bay of Bengal and Straits of Malacca. 
H. elegans (fig. 80).—Yellowish-white, 
back with transverse rhomboidal black 
spots, separated by a series of small black 
spots; belly with black spots or cross- 
bars; head blackish, with a more or less 
distinct light crescentic marking across 
the snout, from above the eyes. 
Total length, 710 millimetres ; ‘tail 60. 
Habitat : North coast of Australia. 
H. gracilis —Bluish-black or greyish, 
olive above in the adult, with more or less Fy¢. 80.—Hydrophus elegans. 
distinct lighter cross-bands anteriorly. (ÉRERRERRE) 
Young sometimes with rhombic black 
cross-bands extending to the belly, or sub-interrupted on the sides. 
Total length, 1,020 millimetres ; tail 90. 
Habitat : Coasts of Persia, India, and Ceylon; Malay Archipelago. 
H. cantoris—Body dark olive or blackish anteriorly, with 
yellowish cross-bands above; posterior part of body olive above, 
yellowish on the sides; tail with olive vertical bars; a blackish 
streak along the belly. 
