A MONOGRAPH OF THE SHA-SNAKES (HYDROPHIINA). 213 
the fore, and midbody being repectively 28, and 33 to34. I holdthat the costals carry 
greater weight than the postoculars and temporals. ‘The latter, in this specimen, con- 
form to the generality of examples of cyanocincta, but these shields being subject to some 
A B Cc 
Fig. 23.—Distiva longiceps. After Gunther, Rept. Brit. Ind., pl. xxv, fig. O. 
variation in both these forms prompts me to regard them as abnormal in this instance. 
The one other departure from the normal mentioned by Mr. Boulenger is the 
juxtaposed character of the posterior costals. Personally I found it extremely hard 
to decide for myself whether these scales were imbricate or juxtaposed, and finally 
decided they were juxtaposed dorsally and subimbricate ventrally. I do not attach 
sufficient weight to this character to consider it should justify separating this form from 
spiralis, and even granting that the scales are juxtaposed ventrally behind, the fact 
that Mr. Boulenger himself in one case at least, viz., fasciata (Schneider), places speci- 
mens with the scales imbricate, together with others that are juxtaposed, makes it 
probable that a similar deviation from the normal may be expected in other species. 
wrayt (Boulenger).—As recently as 1900 Mr. Boulenger described this as a new 
species from a specimen sent from Perak. I have examined the three available 
specimens so labelled in the British Museum, the only ones known. One of them is 
so labelled by an oversight, for it is obviously a very typical specimen of gracilis (Shaw). 
Of this there is no possible doubt. The other two I examined beside specimens of 
spiralis and brugmansi, but failed to detect in them one feature by which they could 
be distinguished. One of them is peculiar in having no marginals. Referring to 
Mr. Boulenger’s description of D. wvayi,' and comparing it with his description of 
brugmansit in his catalogue, I find they completely agree, except in two extremely 
minute details, viz., the length of the frontal which it is claimed is rather shorter in 
wrayi, and carination which is more pronounced in wray?. Such minute differences, 
especially affecting features which are subject to considerable variation, appear to me 
very unconvincing. I cannot even agree that the differences claimed are any more 
noticeable than is seen in certain examples of bragmansii in the British Museum. 
fowert (Boulenger).—This is known from two specimens only, both in the British 
~Museum. Though placed by Mr. Boulenger with his genus Hydvophis, the post- 
maxillary teeth are grooved, and had this circumstance been noticed by him, I cannot 
but think he would have referred them to brugmansiu. From this species I can only 
separate it by (1) the absence of marginals, and (2) the failure of the preefrontal to 
meet the second supralabial. The absence of marginals is remarkable, the only other 
instance of these shields being wanting among the specimens I consider alike being 
! Ann, and Mag, Nat. Hist. v, 1900, p. 307. 2 UII, p. 293. 
