442 DR. J. E. GRAY ON THE AMPHISBENIANS. [May 23, 
The three hinder vertebree have no distinct lower lateral processes ; 
their place is only marked by three slight ridges on the lower edge 
of the hinder side of the mass. The upper lateral processes of the 
hinder cervical vertebrze are small, slender, forming a strap-like sec- 
tion, rather tapering towards and truncated at the tips on the side of 
the apertures for the passage of the nerves for the neural canal. 
The neural canal is rather large, oblong transverse, the height being 
about two-thirds of the width ; it is rather larger and higher behind. 
The hinder surface of the body of the last cervical vertebra is ob- 
long transverse, about two-thirds of the height of its width at the 
widest part; the lower edge is rounded and rather angularly pro- 
duced in the centre, and the upper margin transverse, with a slight 
central depression; the surface is concave, with a central, linear, 
perpendicular, compressed line. 
The cervical vertebrze in Catodontide are united into a single mass 
py their bodies, the neural arch, and the lateral processes. The 
lateral processes of the anterior vertebree are produced, and form a 
thick, subconical, triangular prominence on the side of the mass. 
The front side is nearly flat, and the lateral processes of the hinder 
vertebrze are shorter and shorter to the last. The hinder surface 
shelves from before backwards, and is crested with some conical pro- 
minences which indicate the lateral processes of the different ver- 
tebree of which the mass is formed. The first dorsal vertebra is 
sometimes partially anchylosed with the seventh cervical. 
The arm-bones are very short. 
3. A Reviston oF THE GENERA AND SPECIES OF AMPHISBZ- 
NIANS, WITH THE DESCRIPTIONS OF SOME NEW SPECIES NOW 
IN THE COLLECTION OF THE British Museum. By Dr. 
Joun Epwarp Gray, F.R.S., F.L.S., V.P.Z.S., Erc. 
Sir Andrew Smith having kindly presented to the British Museum, 
along with a number of other reptiles which he has described, the 
types of his genus Monotrophis, which I had not before seen, and 
having received from Mr. Welwitsch and from the collection of my 
late excellent and lamented friend Dr. Balfour Baikie two Amphis- 
bzenians from Africa, and from Mr. Bates a species from the Amazons 
which I believed had not hitherto been recorded in the Catalogue, I 
proceeded to examine them; and, for the purpose of making the 
comparison the more complete, I was led on to study all the speci- 
mens of this tribe which we have in the Museum. 
The natural result of such an examination was, that I was dis- 
satisfied with the manner in which the species had hitherto been 
arranged and described, and, after repeated examination, I have 
reduced my observations to the following results :— 
The determination of the species themselves, and the means which 
a paper resulting from the re-examination and comparison of all the 
species in a large collection afford to a student, are much more cer- 
tain than any isolated description of the species regarded as new, 
