410 FOSSIL FISH. 



may even be doubted if it be a silurus at all, though something 

 like barbies are to be distinguished on each side of the mouth. 



The impression under which the name of Silurus cattus is 

 put is so incomplete, that it is impossible to determine any- 

 thing concerning it, except that it is a fish, and may perhaps 

 be exocetus exiliens. 



As for the Silurus ascita in the Ichthyolithology, the im- 

 pression is sufficiently complete to prove that it was an abdomi- 

 nal fish ; but the general form, or fades, has evidently but 

 little relation with this species of Silurus. 



Herring (^Clupcea). C. murcBnoides, De Blain. This im- 

 pression is entirely in profile. The muzzle, which is trun- 

 cated, belonged to a regular fish, a little compressed in its 

 form. It has been referred by Volta to Salmo murcena, but 

 there is nothing whatsoever about it that can characterise a 

 salmon ; but, on the contrary, the size of the opercle, the 

 great bifurcation of the tail, and the shortness of the body, 

 appear to indicate a species of herring. 



C. cyprinoides, De Blain. A fine impression of a fish, 

 with the head rather small. The aperture of the opercle, or 

 gill-cover, seems to have been very large ; the pectoral fins are 

 placed immediately after ; theventrals are exactly opposed to 

 the dorsal, which is single, narrow, rather high, arched like a 

 scythe ; but its first ray is by no means very long, which is a 

 very distinct character of Salmo cyprinoides, to which this 

 fossil has erroneously been referred. The caudal fin is 

 remarkable for its size, its deep bifurcation, and the sharp 

 form of its lobes. 



C. evolans, De Blain. Though, on the first view, this im- 

 pression bears some resemblance to an exocoetus, or flying-fish, 

 in consequence of the extent of its pectoral fins, this notion 

 will not bear the test of close examination. The pectoral fins are 

 far from being so large as those of exoccetus ; the same is true of 

 the ventral. The head also appears to have been too thick ; 



