364 Messrs. Hancock & Atthey on Reptile- and Fish-Remains 
never could have written as he has recently done respecting 
Paleoniscus, Amblypterus, Pygopterus, Polypterus, and Lepi- 
dosteus. 7 
- Acanthodopsis Wardi,.sp., Egerton. 
For some time past one of the authors of this paper has had 
in his collection several jaws of a fish with large triangular 
teeth, five or six in number, and appearing like processes of 
the bone; and of so peculiar a character are they that it was 
impossible to say even to what family of fishes they belonged. 
It was not until similar specimens were found associated with 
other remains, that any light could be obtained respecting 
them. At length a crushed head or two were robdsieat aki 
biting the same peculiar jaws with the like curious teeth 
attached, lying in juxtaposition with the spines of one of the 
Acanthodet, wattiadly buried in what appeared to be the broken- 
up skin of the fish, crowded with minute rhomboidal scales. 
In one specimen the two pectoral spines are placed in their 
proper position behind the head, and united to it by the con- 
tinuity of tissue, so as to leave no doubt that they and the 
head belonged to the same fish. ‘The uniting tissue, too, was 
mainly composed of granule-like scales of a lozenge-form. A 
_ tail likewise of an Acanthodian has occurred in the same 
locality, the scales on which agree both in size and character 
with those found with the heads. It is therefore quite certain 
that the jaws alluded to belong to the Acanthodet, notwith- 
standing the abnormal character of the teeth, which in this 
family are usually described as minute and conical. 
In the genus Acanthodes, indeed, the teeth appear to have 
been determined only in one species, though M. Aoabae states, 
in his description of the genus, that fine teeth disposed in 
a simple range appear to garnish the circumference of the 
mouth *. The species in which the teeth have been deter- 
mined is A. pusillus; and of this the same author writes that 
the mouth is “ garnie de trés-petites dents qui, méme sous une 
trés-forte loupe, ne paraissent que comme des petits points 
noirs”’ 7. ‘This is so definite that it is impossible to doubt its 
accuracy ; we are therefore forced to the conclusion that in 
this genus, as at present understood, there are two very dis- 
tinct kinds of dentition, so distinct, indeed, that it seems ne- 
cessary to establish a new genus for the reception of those 
species which, like A. Wardi, may have large triangular 
teeth, similar to those alluded to, We therefore propose the 
generic appellation of Acanthodopsis for those Acanthodet 
with this peculiar dentition. 
* Poissons Fossiles du Vieux Grés Rouge, premiére liyraison, p. 89. __ 
+ Ibid. p. 36, 
