MR. G. S. WEST ON OPISTHOGLYPHOUS SNAKES. 419 



On two little-known Opistlioglyplious Snakes. By G. S. "West, 

 A.E.C.S., Scholar of St. John's College, Cambridge. (Com- 

 municated by Prof. Gr. B. Howes, Sec. Linn. Soc.) 



[Eead 19th March, 1896.] 



(Plate XVIII.) 



Having been recently engaged at the Eoyal College of Science, 

 London, in an investigation o£ the buccal apparatus of the 

 opisthogiyphous ophidians *, there were forwarded to me a few 

 months ago by Prof. Howes a couple of snakes, and with them a 

 note asking me to examine their buccal characters. At the same 

 time I also received a letter from Mr. Gr. A. Boulenger asking 

 me to clear up as much as I was able with regard to their glauds 

 and teeth. One of the snakes was an Erythrolamprus, and the 

 other an animal about which there was a doubt as to whether it 

 was an aglyphous variety of Erytlirolamprus or some other 

 snake. The latter was one of three specimens from Nicaragua, 

 all of which were aglyphous, which had been regarded as an 

 aglyphous variety of Erytlirolamprus by Dr. GUntherf. In 

 externa] features and coloration the snakes were absolutely 

 identical, but if their dentition and buccal characters differed, it 

 was possible, as suggested by Mr. Boulenger, that the aglyphous 

 one might belong to a genus closely allied to Liophis. 



The following is a description of the glands and teeth of the 

 first snake, viz. : — 



Ebttheolampeus ^sculapii, Giinth. 



The poison-gland (fig. 1 ff.p.) is a large pear-shaped mass having 

 a slight sigmoid curve ; its anterior pointed end is situated 

 under the eye, and its posterior end reaches almost to the arti- 

 culation of the mandible. It exhibits a marked lobulation, the 

 lobules being arranged in series converging towards the central 

 duct, which leaves the gland at about the middle of its ventro- 

 internal face and passes in a slightly forward direction to the 

 base of the first grooved tooth. 



As in other opisthogiyphous snakes, the poison-gland is not 



* Cf. P. Z. S. 1895, pp. 812-820. 



t Piol. Central!- Americ, Part exxi. p. 166. 



