622 



OPHIDIA COLUBRIDAE 



shield, cuveriug the end of the snout, is much broader than high. 

 The coloration is variable, but there is always a pair of elongated 

 blackish spots or a U-shaped mark on the nape. 



Sub-Fam. 3. Rhachiodontinae. — Witli only a few teeth on 

 the posterior part of the maxillaries, on the palatines and 

 dentaries. Some of the vertebrae in the region of the lower neck 

 have strongly developed hypapophyses, which are directed forwards 

 and pierce the oesophagus. They are used for filing through or 



j]}EDuTf)(rrt) 



Fig. 166. — Dasypdtis scabra. x J. 



breaking the birds' eggs which seem to be the chief food of these 

 snakes. 



Dasijpcltis scahra, the only species, inhabits Tropical and South 

 Africa ; although it reaches scarcely more than two feet and a 

 half in length, such a specimen is able to swallow an ordinary 

 fowl's egg. Pigeons' eggs are swallowed by snakes little more 

 than one foot in length, which seems at first sight quite im- 

 possible. The swallowed egg distends the skin to its utmost 

 capacity ; it then slides down furtlier, the snake makes some 

 slight contortions and the swelling collapses ; after a while the 

 broken and sucked-out shell is vomited out as a crumpled up 



