VISCERA 79 



it is not a prolongation of the true lung, nor does it 

 represent the missing left lung, as has been believed 

 by some authors. 



The glottis has a longitudinal slit, and can be pro- 

 jected forwards when the pharynx is obstructed by a 

 voluminous prey. An epiglottis is usually absent, or 

 represented by a rudiment. It is, however, present in 

 some large American species of Coluber (Pityophis), said 

 to produce, when hissing, a loud and hoarse sound 

 which has been compared to the bellow of the bull — 

 hence the popular name of Bull-snakes by which they 

 are known. It has also been found in a few allied 

 species from Mexico, for which the genus Epiglottophis 

 has been proposed. This epiglottis is a narrow, thin 

 flap, erect in front of the glottis; it is not hinged, and 

 therefore not capable of falling down to cover the 

 opening of the windpipe during the process of swallow- 

 ing, its function evidently being to increase the sound 

 produced by the escape of the air from the windpipe. 



The larynx is represented by two longitudinal 

 bands of cartilage, united by transverse bands ; it is 

 extremely long in some snakes (Leptognathus). 



The oesophagus, which may be extremely elon- 

 gate, sometimes measuring almost one-third of the 

 digestive canal, passes into the tubular or sac-like 

 stomach, often with thickened walls, which itself 

 gradually or abruptly merges into the narrower in- 

 testine. The windings of the small intestine are 

 connected by ligamentous tissue, and enclosed in 



