22 Journal of the F.M.S. Museums. [Vol. X, 



also differ from the Gulf series, but shew a tendency to 

 revert back towards the Malaccan form. The variation is 

 as follows : — 



Gulf of Siam. 



25 to 27 scales round the neck. 37 to 41 round the 

 body. Ventrals, 358 to 401. Av. 377. 



Number of specimens examined, 18. The frontal is 

 as long as its distance from the rostral in 17, shorter than 

 in one. 



Straits of Malacca. 



27, usually 29 to 31, scales round the neck. 39 to 45, 

 usually 41 to 43, round the body. Ventrals 328 to 396. Av. 

 367. 



Number of specimens examined, 50. The frontal 

 shield is as long as its distance from the rostral in 33 

 examples, shorter than in the remainder. 



Cap St. Jacques. 



29 to 30 scales round the neck. 41 to 43 round the 

 body. Ventrals, 387 to 400. 



The frontal shield is longer than its distance to the 

 rostral in one example, equal to in two. 



With the typical form of fasciatus as I now conceive 

 it, this species should not be confused, but from atriceps, 

 with its lower scale formula, separation may at times be 

 difficult. The yellow head markings of consobrinus are, 

 however, very consistent, and in fresh specimens an almost 

 infallible guide. A small but very useful differential 

 character in scalation between them is also to be found in 

 the scales behind the parietal shields. In atriceps there 

 are usually three small scales lying in a series between the 

 large posterior temporal shields and behind the parietals. 

 Rarely there are four or two. Consobrinus on the other 

 hand has usually five or six in the series, sometimes four, 

 rarely seven, their number depending upon the size of the 

 posterior temporal shields. As in atriceps, the posterior 

 temporal shield of consobrinus may be divided by a vertical 

 suture into two. 



H. klossi, which in the Gulf has often the same number 

 of scale rows on the body as consobrinus, can be distin- 

 guished by its distinctly imbricate scales, fewer supralabials 

 and proportionately larger head of olivaceous colour. 



Breeding. — A gravid female taken off the coast of 

 Perak in December contained 7 embryos in an early stage of 

 development. Another taken in February contained 5 fully 

 developed young, varying from 330 to 340 mm. in length. 

 The mother measured 880 mm., tail 70. 



Hydrophis fasciatus (Schneider). 

 Aturia lindsayi, Gray, Zool. Misc. p. 61 (1842). 



