1895.] TEETH OF CEBTAUf POISONOUS SNAKES. 817 



teeth of these Snakes are on the external face of the tooth, and 

 are slightly to one side of the axis (PI. I. tig. 16) (this is also the 

 case in Oxyhelis). The blood-vessels supplying the maxillary 

 teeth form considerable blood-sinuses around the bases of the 

 large median teeth ; this was more particularly noticed in 

 D. prashms. These sinuses are in direct continuity with the 

 blood-vessels in the pulp-cavity of the tooth, and lie at the base of 

 the large longitudinal furrow between the pterj^goid and the 

 maxilla. They just underlie the glandular epithelium of the 

 mouth, being separated from it only by a thin layer of connectiye 

 tissue. 



The mandibular teeth increase in size from the first to the fifth 

 in Z). mycterizmis and then follows a series of much smaller teeth ; 

 in D. prasinus they increase in size from the first to the thii'd, the 

 latter being the largest tooth in the head, and these are then 

 followed by 10 smaller teeth. 



Grenus Oxtbelis. 



Species examined : — 0. fulgida. 



The poison-gland is very clearly defined and the superior labial 

 gland is exceedingly long and narrow ; it reaches to the anterior 

 extremity of the maxilla and consists of much smaller lobules than 

 the poison-gland. The inferior labial gland is also greatly elongated, 

 reaching from the antei-ior extremity of the mandible almost to 

 the articulai- condyle, and is more extensive than that of any other 

 of the Snakes examined. The Harderian gland (PI. XLIV. fig. 20) 

 is precisely similar to that of Dryophis. The mpxilla (PI. XLIV. 

 fig. 21) possesses more teeth than th .t of any other of the Snakes 

 examined, there being 20 in one uninierrupted series. The first 17 

 are equal in size and much curved ; the posterior three are a little 

 larger, compressed laterally, and the external face of each possesses 

 a very shallow groove. The muscular folds surrounding these 

 three posterior teeth are not united in fro^t, and in consequence 

 of a thin muscular fold across the base of the anterior grooved 

 tooth the poison-duct in this Snake is placed in communication 

 with the interior of the mouth before it is with the groove of the 

 tooth (PI. XLIV. fig. 22). 



The mandibular teeth are 18 in number. The first 8 are of 

 equal size and slightly large'" than the ma^Ulaxy teeth ; these are 

 followed by 10 much smaller closely-set teeth. 



The only difference between this genus and the preceding one 

 (^Dryophis) is lq the abserce of the large median maxillary fangs 

 and in the circular pupD, the latter being elongated in a horizontal 

 direction in BryopMs. 



Genus Eteikodipsas, 



Species examined : — E. coluhriens. 



The poison-gland is clearly defined and the lobules are very 

 small ; the superior labial gland is rather more extensive than usual 



