A MONOGRAPH OF THE SHEA-SNAKES (HYDROPHIIN 22), 225 
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specimens from Burma. I consider the species fairly well differentiated, but it is in 
most respects extremely like cyanocincta. The prefrontal, however, does not touch 
the second labial, in which respect it differs from cyanocincta 
I find the head shields in this species very liable to be broken up, especially the 
supralabials, and many departures from the type-specimen are, in consequence, to be 
met with. This I will refer to again 
Fig. 40 —Distira hendersont. After Boulenger, Journ. Bomb. Nat. Hist. Soc., vol. xiv, p. 7109. 
Distiva hendersoni.— This is known from a single specimen from Burma described 
by Mr. Boulenger. A specimen very like it I referred to under that title in the paper 
I wrote on the Sea Snakes in the Indian Museum. I remarked at the time upon the 
very close affinities between this and n7grocinctus (Daudin). Now that I have 
examined the types of both and the other specimens of nzgrocincta in the British 
Museum, I feel convinced that the two forms are identical, though this view is not 
borne out by the first glance at the figures I attach herein—the one from Gtinther 
representing one of General Hardwicke’s specimens labelled nigrocinctus, and the other 
reproduced from Boulenger’s figure of the type of hendersoni. 
The most important distinction between the two claimed by Mr. Boulenger affects 
the posterior maxillary teeth, which, he observes, are grooved in hendersoni. J find 
these teeth also grooved in nigrocincta. In colour and markings the two are peculiar 
and exactly similar. In the numbers of the scales, ventrals, and in most of the head 
shields, the two are alike; the apparent differences affecting the latter only, I think, 
obviously arise from a tendency many of these shields have to division. This same 
tendency, I may remark, is seen in certain other well defined species, viz., cyanocincta, 
ornata, viperina, ete. It is particularly noticeable in the supralabials and nasals, 
though by no means confined to these shields. 
The type-specimen of hendersoni has, I consider, the second, third, fourth, fifth 
and sixth supralabials divided on the left side, and the second, third, fifth and sixth 
on the right. The upper part of the second Mr. Boulenger considers a loreal, the 
upper part of the third a preocular, and the upper parts of the fourth and fifth on 
the left side suboculars. On the right side the fourth, being undivided, touches the 
eye; but if my view, which appears to me the obvious one from analogy, is accepted, 
the third, fourth and fifth labials touch the eye on both sides. Now some of these 
shields are similarly divided in specimens labelled nigrocinctus in the British Museum, 
viz., in two out of the three available specimens. (The fourth has been already referred 
to as a wrongly identified specimen of cyanocincta). In the type, and in Bleeker’s 
specimen, a similarly formed ‘‘ pseudo loreal’’ is to be seen on the left side only. 
In the type-specimen the first supralabial is divided into an upper and a lower part. 
