692 REPORT OF NATIONAL MUSEUM, 1898. 



iuclosiug a tube. In the Soleuoglypha tbis union has become complete 

 fusion so that no trace of the primitive groove remains, altliough it is 

 distinct in individuals at birth. The foramen at the anterior base of 

 this tooth in Proteroglyplia and Solenoglyplia receives the i)apilliform 

 extremity of the etferent duct of the salivary poison gland, and thus 

 conducts the poison to the slit-like opening at the front apex of the 

 crown. 



The tongue is long and cylindric, and is retractile into a sheath 

 which opens in the anterior part of the floor of the mouth immediately 

 in front of the glottis. Its free extremity is deeply bifurcate. It is 

 the only tactile organ of the Serpentes. 



The alimentary canal is elongate, and the stomach is a simple enlarge- 

 ment of its diameter, without transverse curvature. It passes gradu- 

 ally into the small intestine, which is more or less convoluted by short 

 turns which adhere together and are inclosed in a common peritoneal 

 fold, which does not follow the convolutions, as is the case in Sauria 

 and other Yertebrata. The rectum is straight, of enlarged diameter, 

 and of variable length. It is separated from the small intestine by a 

 muscular constriction, which is passed at one side by a narrow commu- 

 nicating tube, which frequently leaves a rectal ctecum at one side. 

 The walls of the stomach are often thickened, while those of the small 

 intestine are variable, and are frequently densely papillose. The rec- 

 tum presents a variety of internal structure. Its internal wall is 

 smooth in Eunectes murinus, Eryx thebaicus, and Gylindrophis riifa. It 

 has longitudinal plicas in Ilysia scyfale, Coluber obsoletnSj Gommosoma 

 corais, Zamenis Jiagelliim, Katrix taxispilotiis, Honialopsis lencobalia, 

 Hydrophis striata. With longitudinal folds there are transverse ones 

 more or less developed in OpMbolus polyzonus, Malpolon lacertinnm^ 

 Bryophis prasina, Ghersydrus granulatus. There are free transverse 

 folds more or less developed in Leptognathus fasciata, Dipsas dendro- 

 phila, Oxybelis acuminata^ Vipera ammodytes^ Grotalus durissus. The 

 rectum is divided by transverse septa, with a perforation median or 

 lateral, in Python spilotis, Farancia abacura^ Boodon geometricus, Elaps 

 surinamensis, Bungarus sp., Ancistrodon contortrix. 



The salivary glands are labial or external to the maxillary and man- 

 dibular bones, and have numerous efierent ducts. In opisthoglyph 

 snakes that portion of them which is opposite the posterior maxillary 

 teeth is enlarged, and the secretion is discharged at the bases of the 

 grooves of the teeth. In proteroglyph and solenoglyph snakes tbis 

 gland is still further developed, and fills the space between the orbit 

 and quadrate bones. Its efiferent duct extends as a tube along the 

 superior surface of the maxillary bone. In the genus Gausus this gland 

 is greatly elongate, extending posteriorly above the ribs for one sixth 

 the length of the animal (Reinhardt). In the Elapid genus AdeniopJiis 

 the gland is restricted to a position corresponding to the posterior 

 extremity of that of Gausm, and has in consequence an efferent duct 

 of extraordinary length (Meyer). In these types a portion of the tern- 



