258 CLASS REPTILIA. 



Xenopeltis, Reinw., 



Have behind the eyes large triangular plates, and 

 imbricated ; so that they are confounded with the 

 scales that follow, and which are merely smaller.* 



Heterodon, Beauvois, 



Have the usual plates of the adders, but the end of 

 their muzzle is of one piece, short, and formed like 

 a three sided pyramid, a little raised, and one ridge 

 of which is above, which has caused them to be 

 named serpents, with the snout of a hog.t 



The HuRRiAjt Daud., 



Are adders of the East Indies, in which the plates 

 of the basis of the tail are constantly simple and 



* Xenopeltis Concolor, Reinw. 



-j- Heterodon Noiratre, Beauv., Heterodon of Daud., and Heterodon 

 Tachete {CencJiris Mokeson, Daud.), belong to this genusj but Beauvois has 

 established it on a character which is found in a great number of adders, 

 of having the hinder maxillary teeth larger, and Daudin appears to have 

 been acquainted with his Mokeson only by a drawing. We understand 

 by it the Hognose of Catesby, II. pi. Ivi. which Daudin himself has cited. 

 It has sometimes a portion of the plates of its tail entire ; but at its basis, 

 and not at the end, as Daudin tells us. Linnaeus indicated this serpent 

 very well in his tenth edition, under the name of Coluber Constrictor ; we 

 cannot tell wherefore he should have changed it in his twelfth edition to 

 Boa Contortrix. 



t Hurriah is a barbarous name derived from that given in Bengal to 

 the species represented. Russ. xl. copied. Daud. V. Ixvi. 2. Another, 

 Merrem, II. iv. 



