THE CLASSIFICATION OF THE OPHIDIA. 211 



The penial characters of the Solenoglypha are like those of the more specialized 

 members of the Colubroidea, and vary in the same way, except that the sulcus and 

 the organ are always bifurcate. 



Atractaspididae. 



The genera of this family are the following : 



I. No internasal plates. 



Urosteges one-rowed ; anal entire Braclvycranium Hallow. 



II. Internasals present. 



Uroateges one-rowed ; anal entire Atractaspis Smith. 



Urosteges more or less two-rowed ; anal divided * Olothelaps Cope. 



The only genus in which the hemipenis is known is Brachycranium. Here the 

 sulcus and entire organ are furcate, and spinous to near the extremity. The latter is 

 furnished with wrinkled lamina?, which enclose a few irregular calyces at the apex, and 

 below these are transverse farthest from the sulcus and longitudinal nearest to it. The 

 spines are in longitudinal series. The only species examined (B. coi'pulentum Hallow.) 

 is not deeply bifurcate, and the bifurcation of the sulcus corresponds with that of 

 the organ (PL XXXII, Fig. 6). 



Causidae. 



Subcaudals two-rowed ; anal entire ; scales keeled ; rostral prominent, witli recurved border. 



Heterophis Pet. 



Subcaudal and anal plates double ; scales keeled ; rostral normal Gausus Wagl. 



Subcaudals and anal entire ; scales smooth ; rostral normal ; a loreal Dinodipsas Pet. 



Subcaudals two-rowed ; anal entire ; scales smooth ; rostral normal ; a loreal, and one nasal plate. 



AzemiopJiis Boul. 



The only genus which I have been able to examine as to the penial structure is 

 Causus. The sulcus and organ are deeply and equally bifurcate and the branches are 

 extensively calyculate, while the median portions are spinous. The calyculate region 

 is traversed by a deep groove, which is bound on one side by a longitudinal ala. The 

 calyces are replaced in the groove by depressed laminse, while the opposite side of the 

 ala supports the usual structure. The borders of the calyces are serrate in the 

 a rhombeatus (PI. XXXII, Fig. 7). 



The characters are in general like those of the typical Solenoglypha. 



Viperidse, 



I. Urosteges two-rowed. 

 a. Apex of hemipenis calyculate. 



No flounces ; calyces deeply fringed ; nostril between two plates Vipera Laur. 



" Nostril between three plates " (Gthr.) •• Daboia Gray. 



*Type Atractaspis hildebrandtii Peters ; second species, A. congica Peters. 



