1920.] Dr. Malcolm Smith : Sea Snakes. 21 



prae- and one, rarely two, postoculars ; a single large 

 anterior temporal succeeded by another not so large, and 

 with 4 to 7, usually 5 or 6, small scales in a series between 

 them and behind the parietals. Six supralabials, 2nd 

 largest and in contact with the praefrontal, 3rd and 4th 

 touching the eye, 6th very small. Chin-shields well deve- 

 loped, subequal, the posterior pair in contact or partly 

 separated. Four infralabials in contact with the chin- 

 shields. 



25 to 31 scales round the neck, 36 to 45 round the 

 thickest part of the body, those on the neck imbricate, 

 elongate, with truncated apex, those posterior hexagonal, 

 subimbricate, with a small tubercle or short keel. Ventrals 

 distinct throughout, bicarinate, 328 to 401. 



Colour. — Greyish above, yellowish or whitish below, 

 with dark grey bars or bands, 60 to 80 in number. In the 

 fore-part of the body these bands are as broad above as 

 below, and broader than their interspaces ; behind broadest 

 on the back, narrowing on the sides, and usually incomplete 

 across the belly. Head blackish or greyish, with a curved 

 yellow mark, its front on the nostrils, and reaching back 

 along the sides of the head. Often a connecting bar across 

 the frontal and another across the parietal shields. With 

 age these markings lose definition. 



Variation. — The frontal shield touches the nasals in 

 one example ; the anterior temporal by fusion with the 

 6th supralabial sometimes reaches the border of the mouth ; 

 fission of the 2nd supralabial in one example produces a 

 pseudo-loreal (No. 2216) ; marginal fragmentation of the 

 supralabials is not present in any example ; usually there 

 is a single cuneiform scale after the third infralabial. 



Dentition. — Posterior maxillary, 5 ; palatine, 7 ; 

 pterygoid, 15 or 16 ; mandibular, 13 or 14 (3 specimens 

 examined) . 



Type. — Adult male, author's number, 1132 ; collected 

 at the mouth of the Bangpakong river, Inner Gulf of Siam, 

 in February, 1917. 



Habitat. — Coasts of the Malay Peninsula, Siam and 

 Cochin China. 



Remarks. — H. consobrinus appears to be most nearly 

 related to H. brookii Giinther, and H. floweri Boulenger, 

 two species described from the north coast of Borneo ; and 

 it is not unlikely that it will ultimately have to be united 

 with one or other of them. Neither, however, accord 

 entirely >vith the scalation presented by my large series of 

 consobrinus, and until more is known about the variation 

 existing in these two forms, I leave mine distinct. 



With the true status of this snake therefore still uncer- 

 tain, I refrain from describing geographical races, although 

 the form found in the Straits of Malacca is quite distinct 

 from that found in the Gulf. The case is further com- 

 plicated by the three examples from Cap St. Jacques, which 



