THE XENODONS. 407 



to the simple teeth in the same jaw and on the palate, 

 and which are not bigger than the palate teeth seen behind 

 the recumbent fangs of Daboia, p. 349. 



Of these true Xenodons there are eight species ; but 

 the strange-toothed group includes Tomodon, Heterodon, 

 Simotes, Liophis, and several others that have large 

 posterior teeth, some of which are grooved, others not, 

 but all without a poison gland. 



Searching page after page about Xenodon, something 

 one day suddenly caught my eye that had hitherto escaped 

 notice. In his Odontography, Owen, describing the South 

 African snakes BiicepJiali, says : ' Their long grooved fangs 

 are firmly fixed to the maxillary bone, or are slightly 

 moveable according to their period of growth ; they are con- 

 cealed by a sheath of thick, soft gum, containing loose, 

 recumbent, grooved teeth ready to succeed those in place.' 



' So, then, a mobile tooth was already known to science.' 

 Of Bucephali viridis, Dr. Andrew Smith describes the ' pos- 

 terior or mobile and grooved teeth of the maxilla.' He says : 

 * Some are placed for immediate use, the rest are recumbent 

 between those and the inner portion of the spongy sheath 

 which envelops them ; anterior teeth fixed.' He considered 

 these back teeth not poisonous, but only for holding or 

 preventing the escape of food. * They may convey an acrid 

 saliva.' Still we are not informed hoiu the teeth move.^ 



These snakes — the Bucephali — like the far-famed horse 

 of Alexander the Great, owe their name to their large, 

 ox-shaped head. They are the ' Boomslangc ' or tree 

 snake of the Dutch settlers, and are by some ophiologists 



^ Zoology of South Africa. 



