1893.] Zoology. 479 
may extend to the apex, but they rarely extend to the base. The sur- 
face may, however, be laminate and not recticulate, and the laminæ may 
be longitudinal or transverse. In either of these cases they may not 
be spiniferous. The apex or apices of the organ may be furnished 
with a rigid papilla or awn. The entire surface of the organ 
when protruded, is designed for the maintainance of its position in 
the oviduct of the female, from which it cannot be withdrawn, except- 
ing by invagination. 
In the Tortricina and Peropoda, the hemipenis is not spinous, and 
the sulcus is bifurcate, and in the Boidae the hemipenis is bifurcate also, 
although in some genera (Xiphosoma, Ungualia), the branches are very 
short. The external integument is never reticulate, but is always 
laminate with elongate papill at the extremities, in Epicrates, Xipho- 
soma, and Ungualia. The laminae are pinnate from the sulcus as an 
axis, in Morelia, Enygrus, Lichanura and Eryx, and are transverse 
in Charina. In Ilysia they are pinnate, with a few longitudinal plicæ 
below. 
The general definitions of the families exclusive of the Peropoda are 
as follows. 
No spines; surface longitudinally plicate ; Calamariide. 
The surface of the hemipenis is flounced more or less transversely; Lycodontide. 
F ace is more or less reticulate, and the sulcus spermaticus is undivided ; 
kei eae anterior ; Colubride. 
The surface is reticulate or JongimdinaHy plicate, and the sulcus is divided ; hypa- 
pophyses anterior Xenodontide. 
The surface is Dras reticulate nor flounced, and the Peson when present are dis- 
connected; hypapophyses continued to caudal verteb Natricide 
The Calamariidæ approach in the oon of the hemipenis to 
such Peropoda as Eryx. The character assigned to the Lycodontide 
is more or less distinctly present in the typical or Solenoglyph venomous 
snakes; while the Najide (exclusive of Elapide) on the other hand, 
cannot be distinguished from the Xenodontide, by any general char- 
acter. The Lycodontide are Old World with a single genus in America; 
a distribution resembling that of the Pythonide. The Colubride 
inhabit the Old World and North America, a few genera entering 
uth America. The distribution is like that of the firmisternial 
By tia. The Xenodontidsx are of South America and Madagascar, a 
few genera entering Africa and North America, a distribution nearly 
like that of the Iguanian lizards. The Natricide are distributed in 
the Northern Continents, very few types occurring in Africa and none 
in South America 
