MISCELLANEOUS NOTES. 861 



It will be seen that the males, all of which had their genitals extended 

 and were therefore easily sexed, considerably outnumbered the females, 

 there being 10 of the former to 4 of the latter. 



Sexual differences are apparent. The S 6 , which measured from 11 to 

 11^ inches, show a very slight tendency to exceed the 5 § in length, the 

 latter ranging from lOf to 1\\ inches. Males again usually exhibit a. 

 decidedly smaller number of ventrals, these varying from 319 to 353, as 

 compared with 344 to 370 in the females. The number of these shields 

 between the anal and navel is of no account, there being from 23 to 27 in 

 the S , and 24 to 25 in the § . Females tend to have a larger number of 

 costals in all parts of the body length but especially behind. Anteriorly (2 

 headslengths behind the head) they number 29 to 30, against the male 27 

 to 29, in midbody they are 33 to 35 against the male 28 to 33, and pos- 

 teriorly (2 headslengths before the anus) they are 34 to 36 against the male 

 30 to 32. 



Lepidosis. — All the specimens agreed in having the praefrontal in 

 contact with the 2nd superlabial (except on the left side of No. 14 where 

 it just failed to touch), one praeocular, one postocular, and the posterior 

 sublinguals in contact. 



Markings . — The markings of the brood show considerable variation. 

 The rings are mostly of very even width and complete. Some show a 

 slight, and others a more decided tendency for the rings to dilate verte- 

 brally. In some they are discrete ventrally, in others dilated, especially 

 anteriorly, and in others more or less connected by a ventral black band. 

 The vertebral spots that occur in the interspaces are very variable. In one 

 specimen they are quite absent, in another there is one faint spot in front 

 and two faint behind, in others they form a fairly continuous series. In 

 the majority there are no ventral spots in the interspaces, in some these are 

 distinct, and in one the ventral band connecting the rings dilates in each 

 interspace. In all the rings are all or mostly complete, on the other hand 

 in some they are incomplete ventrally, especially behind. 



In the parent the rings are not connected ventrally but are interrupted 

 posteriorly, and there are but two vertebral spots. 



The differences to be seen in the individuals of this brood are very in- 

 structive, and entirely support opinions expressed by me in my monograph 

 of the Sea-snakes* with regard to the two forms Hydrophis spiralis (Shaw) 

 and Distira brugmansi (Boie), which Boulenger considered distinct, f 



In my monograph (page 210) I gave reasons for believing that these two 

 forms were not species distinct from one another. The former was placed 

 in the genus Hydrophis by Boulenger on the assumption that the post 

 maxillary teeth are not grooved, whereas in the latter, which he placed as a 



* Mem. Asiat. Soc, Bengal, 1909, p. 177 and 178. f Cat. Vol. III. 

 40 



