Class 4. Beptilia. Order 2. Ophidia. 



423 



by the absence of a tympanum and tympanic cavity; the very 

 long body, the relatively short tail; the broad scutes covering the 

 ventral surface ; the connection of the mandibular rami by an elastic 

 ligament; the great mobility of the quadrate and the whole jaw 

 apparatus ; and by the long, bifid tongue. They are distinguished 

 from apodous Lizards by the possession of the elastic ligament, 



0-- 



Fig'. 348. 4 Poison tooth of a Crotalus, seen from in front and partly from the 

 outside ; B the same tooth cut through longitudinally ; Poison tooth of Naja tri- 

 pudians^ seen in similar view ; D transveL•^e section of the same; JS Transverse section of 

 the tooth of a Crotalus. / groove, g poison canal, o upper, o' lower opening of the poison 

 canal, p pulp cavity. — Orig. 



by the absence of sternum and shoulder girdle (of these parts there 

 are at least rudiments in the Lizards), and by the rudimentary hyoid. 

 On account of the power of widening the buccal cavity, dependent 

 on the great mobility of jaws and palate, and the absence of a 

 sternum, the Snakes are able to take in very large prey; they feed 

 at long intervals (as much as several months). Some snakes (Protero- 

 glrpha and Solenoglypha) are provided with large poison teeth, 

 with a deep groove on the front side ; the edges of the groove may be_ 

 closed or even fused, but it is open at the apex of the tooth. Only 

 one of these teeth is present at a time, anteriorly, in the maxilla of 

 either side, and the aperture leading into its canal is connected at the 



