1920.] Dr. Maixolm Smith : Sea Snakes. 31 



240 to 320 ; praef rentals usually in contact with the supra- 

 labials, 3rd and 4th labials usually touching the eye. 



Habitat. Arabian Sea and coasts of the Indian Penin- 

 sula. 



A Malayan form. 



40 to 55 scales round the neck, 49 to 66 round the body ; 

 ventrals 239 to 292 ; praefrontals usually not in contact with 

 the supralabials (80%), fourth labial only touching the 

 eye (60f^c). 



Habitat. Coasts of the Malay Peninsula, Siam and 

 Cochin China. 



With this latter form I am able to deal ver\' fuUy. 

 Altogether I have examined about 140 examples ; 60 of 

 these are from the Straits of Malacca, and the remainder 

 from the seas East of the Peninsula. 



It is possible, if one cares to go more closely into 

 detail, to separate this form again, the dividing line between 

 them being the Peninsula. As, however, they differ only 

 In a slight variation in the number of body scales without 

 alteration in the head shields, it is preferable to consider 

 them together. The actual variation is as follows : — 



Straffs of Malacca. 



43 — 55 round the neck, 52 — 66 round the body. Ven- 

 trals, 239—278. 



Gulf of Sum. 



40 — 52 round the neck, 49 — 62 round the body. Ven- 

 trals, 239—292. 



In the whole series the praefrontals fail to touch the 

 supralabials in 112 examples. In nearly every instance this 

 occurs on both sides. In the same series the 4th labial only 

 touches the eye in 85. 



Females on the average have from 3 to 4 more scale 

 rows round the nedc and body than males. I find the sexual 

 variation as follows : — 



Straits of Malacca. — Males, 13 — 18 (av. 45) round 

 the neck, 52—60 (av. 55) round the body, ventrals, 239 — 

 270. Females, 45 — 55 (av. 49) round thQ neck, 54 — 63 

 (av. 59) round the body, ventrals, 248 — 278. 



Gulf of Siam. — ^Males, 40 — 48 (av, 43) round the nedt, 

 49—59 (av. 53) round the bodv, ventrals, 243—292 (av. 

 264). Females, 42—52 (av. 46) round the neck, 51—62 

 (av. 56) round the body, ventrals, 239—287 (av. 260). 



Abnormalities in this form are not uncommon, and 

 such faults in development as partially divided frontals, 

 fusion of the frontals with praefrontals, of oculars with 

 labials, and oculars with each other, occur frequently. 

 Fragmenlation of the parietals to f0rm a small interparietal 

 occurs in about 50<^r. 



