THE CLASSIFICATION OF THE OPHIDIA. 199 



Several forms of this family I have not been able to examine, as Chondropython, 

 Sanzinia, Bolieria, Trachyboa, etc. 



Charinidae. 



In Charina the sulcus is bifurcate, but the organ is simple. The surface is plicate, 

 the plicae distant towards the apex, and the apex smooth (PI. XIV, Fig. 3). 



Ungualiidae. 



In Ungualia there are no plicae, and in U. melanura there are only four small 

 papillae symmetrically arranged. The sulcus and organ are furcate (PI. XV, Fig. 8). 



AGLYPHODOXTA. 



The three families of the Aglyphodonta are defined as follows : 



Two pulmonary lungs ; no tracheal lung ; a coronoid bone Xenopeltidm. 



One pulmonary lung and a tracheal lung ; no coronoid bone ; postfrontal bone produced forwards over 

 the orbit ■ Acrochordidce. 



One pulmonary lung, with a rudiment of a second ; rarely a tracheal lung ; no coronoid bone ; post- 

 frontal bone not produced over orbit Oolubridm. 



I have been unable to determine the penial structure of the only species of the 

 Xenopeltidae, the Xenojieltis unicolor Reinwt. as all of the four individuals accessi- 

 ble to me are females. 



Acrochordidaj. 



There are two subfamilies of this family. 



No gastro- or urosteges Achrocliordinm. 



Of the members of this subfamily I have only examined the hemipenis of 

 AcrocJwrdus javanicus and A. granulatus Cuv. This is bifurcate but not deeply, and 

 the surface below the bifurcation is smooth. The branches are delicately and not 

 closely spinous (PI. XV, Fig. 13). It is not certain that the Xothopinae belong to 

 this family or to a distinct one ; the cranial structure is identical. They differ from 

 the Achrochordime as follows : 



Gastro- and urosteges present Nothopince. 



Colubridae. 



The natural divisions of this family are clearly indicated by the characters of the 

 hemipenis for the greater part. The characters of the vertebras cannot, however, be 

 neglected ; and the dentition, in a general way, corresponds with the results thus 

 attained. Thus the type of penis with simple sulcus and well-developed ruches 



A. p. s. — VOL. xviii. z. 



