1128 REPORT OF NATIONAL MUSEUM, 1898. 



SOLENOGLYPHA. 



The families of this suborder are defined as follows: 



Maxillary bone not excaAated; fang not grooved in front; no postfroutal bone 



Atra( TAspiDiD.K Giintber. 

 Maxillary bone not excavated; fang grooved in fiont; a ])ostfrotrtal bone 



Causid.i-: Cope. 

 Maxillary not excavated; fang not giooved in front ; a postfrontal bone 



ViPEKiD.E Gray. 



Maxillary bone excavated by a deep fo.ssa, which opens externally ; fang not grooved 



in i'ront ; a postfrontal bone Cr< >talii).k Graj-. 



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

 specialized members of the Colubridie, and xavy in the same way, 

 except that the sulcus and the organ are always bifurcate. 



ATRACTASPIDID.E. 



The genera of this family are the following: 



Urosteges one-rowed ; anal entire Jtractasjyis Smith. 



Urosteges more or less two-rowed ; anal divided (lotlulaps Cope.' 



The only species in which the hemipenis is known is the Alra(fas2ns 

 corpidentus Hallowell. Here the sulcus and entire organ are furcate, and 

 spinous to near the extremity. The latter is furnished with wrinkled 

 lamina' which inclose 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 ouly species exam- 

 ined (7:>. corpulentum Hallowell) is not deeply bifurcate, and the bifurca- 

 tion of the sulcus corresponds with that of the organ. 



Several species of Atroctaspis are known from Africa. They are 

 ground snakes of snmll and medium size and of dark colors. They 

 have the form of some Calamarian genera, with indistinct head and tail 

 and snmll eyes. They are not reported to be dangerous. 



CAUSID.E. 



Siibcandals two-rowed; anal entire; scales keeled; rostral ])romineut, with recurved 

 border Heterophis Peters. 



Snbcandals and anal plates donlde; scales keeled ; rostral normal.. .Causus Wagler. 



Subcandals and anal entire; scales smooth; rostral normal, a loreal 



Diiiotlipsas Peters. 



Snbcau<lals two-rowed; anal entire; scales smooth; rostral normal, a loreal. and 

 one nasal ])late _ JccDiiojihis Bonlenger. 



The only genus which 1 have been able to examine as to the ])enial 

 structure is Caiisus. The sulcus and organ are deeply and equally 

 bifurcate, and tlie branches are extensively calyculate, while the mediau 

 portions are spinous. The calyculate region is traversed by a deep 

 groove. The calj-ces are replaced in the groove by depressed laminje. 

 The borders of the calyces are serrate in the C. rhombeatus. 



Type Atractaspis hildcbriDuJtii Peters; second species ./. conf/ica Peters. 



