in the Collection of the British Museum. 55 
Leptodira discolor. Mexico. Purchased. 
*Diemansia cucullata. Sidney. G. Krefft, Esq. 
*—— torquata. Norfolk Island. Purchased. 
*Hoplocephalus temporalis. South Australia. Purchased. 
*—. nigrescens. Sidney. G. Krefft, Esq. 
*Callophis nigrescens. East Indies. Fort Pitt Museum. 
Elaps filiformis. Para. Purchased. 
Trimesurus macrolepis, Bedd. Anamallay Hills. Capt. R. H. Beddome. 
Thamnocenchris aurifer, Salv. Guatemala. O. Salvin, Esq. 
achesis nitidus. Ecuador. Purchased. 
Nearly all the species named have been described in the 
* Proceedings of the Zoological Society’ or in this Journal; and 
I subjoin here the descriptions of, or remarks on, those marked 
with an asterisk (*). 
Lowxocemus bicolor, Cope, Proc. Acad. Nat. Sc. Philad. 1861, 
p. 76*. 
The discovery of this snake is one of the most important ad- 
ditions to herpetology made in the course of the last few years. 
I had been in doubt for some time as regards the position which 
this highly interesting form should take in the system, when I 
received Mr. Cope’s excellent description of it. The specimen 
in the British Museum is in very good condition, 18 inches long 
(we are not acquainted with the size of the specimen in the 
Smithsonian Museum), and agrees with Mr. Cope’s description 
so well that we cannot doubt the specific identity of the two 
specimens. Only two points deserve some remarks. First, the 
intermaxillary teeth are present ; there are two, smaller than the 
* In the same part of the Journal quoted (p. 74) Mr. Cope has pointed 
out the identity of Ablabes purpureocauda, Gthr., with Contia mitis, 
Baird & Gir., and of Tropidonotus medusa, Gthr., with Regina Clarkii, 
Baird & Gir. I have no doubt that this observation is fully correct ; but 
I feel rather surprised that the identity of those species should have been 
sted” by one of the authors of the ‘Catalogue of North American 
Reptiles.’ Those authors have considered the number of scales (21, 19, 17) 
as a character of sufficient importance, not only for distinguishing the spe- 
cies, but also for dividing them into separate groups (see Eutainia); they 
have founded a new genus (Contia) on the presence of a single post-orbital, 
and distinguished it by that character from Chlorosoma (Baird & Gir. Cat. 
pp- x. 110). Now, when Prof. Baird suggests that a snake with 21 series 
of seales, and with quite a peculiar coloration of the belly (T. medusa), is 
identical with another with 19 series, and with a different coloration (T. 
Clarkii), and that specimens with two post-orbitals (A. purpureocauda) 
ought to be referred to a genus expressly distinguished from a second 
genus by the character of one post-orbital (Contia), he confesses that his 
views about specific and generic characters in Ophidians have undergone 
a considerable change since the publication of his Catalogue, or he must 
admit that it is impossible to determine from the accounts of the said 
Catalogue those species which he so readily recognized in my descriptions, 
