ORDER OPHIDIA. 255 



Their body is very much compressed. The back 

 carinated. These come from the East Indies, and 

 may give rise to a distinct subgenus.* 

 Schneider has separated from the boa, 



ScYTALE, Merr. (Pseudo-Boa), 



Which have plates not only on the muzzle, but on 

 the cranium, like the adders, no fossets, the body 

 round, the head of a piece with the trunk, as in 

 tortrix.-f" 



Daudin has also separated the 



Erix, 



Which differ in having a very short obtuse tail, and 

 ventral plates more narrow. Their head is short, 

 pretty nearly of a piece with the body, and these 

 characters would approximate them to tortrix, if the 

 conformation of their jaws did remove them from 

 that genus. Their head, moreover, is covered 

 only with small scales. They have no crooks at the 

 arms. 



To til em we may approximate 



* The B. Cannata, Schn., or Ocellata, Opp B. Viperina, Sh. Russel, 

 pi. iv. N. B. These two subdivisions form the genus Xiphosoma of 

 Fitzinger. Cenchuis of Gray. 



t Scytale Coronata, Merr. Seb. II. xli. 1, Pr. Max. 7. liv. N. B. We 

 must not confound the scytalm of Merrem with those of Daudin, which 

 are the ccMa of Merrem. 



