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



The ventral spines of the males appear to be longer 

 and larger in individuals from the head of the Gulf, than in 

 those from any other locality 1 have examined. Possibly, 

 being a sexual character, they increase in size in the breed- 

 ing season. 



Dentition.— Posterior maxillary, 4 to 6* ; palatine, 6 or 

 7 ; pterygoid, 17 to 20 ; mandibular, 14 or 15 (9 specimens 

 examined) . 



Breeding. — In the Gulf young are born in April and 

 May, from 2 to 5 being produced. In length they vary 

 from 250 to 300 mm. 



Aipysurus eydouxii (Gray). 



Aipiisnriis eudoiixii, Boulenger, Fauna Malay Pen., Rept. and 

 Batr., p." 195 (1912) ; Wall, Mem. Asiat. Soc. Bengal, ii (8), p. 189 

 (1909) N. de Rooij, Rept. Ind. Aust. Anhipol. TT. i). 219 (1917). 



Gulf of Siam, 11 exs. 



In three examples the praefrontal is divided ; in one 

 the 3rd and 4th supralabials touch the eye on both sides. 

 The ventral keel is variable ; in four examples it is poorly 

 developed ; in three others each keel in the fore-part of the 

 body bears a strong spinose tubercle, and there is a series 

 of small tubercles along the adjacent row of body scales 

 for nearly the same distance. 



One specimen was caught some 20 feet above high 

 water mark, and in life had a rich slate-blue irridescence. 



Colour. — Yellowish, with from 44 to 55 dark olive 



dorsal bars, which taper to a point on the sides and are 



usually confluent vertebrally. Head dark olive ; entirely 

 black in the young. 



* Boulenger in his description of this genus, gives the number 

 of teeth behind the poison fangs as from 2 to 4. I cannot find any 

 of my specimens with less than 4, 



