396 FOSSIL FISH. 



a great quantity of teeth have been found separate, which is 

 not the case at Glaris ; and because Mount Pilate differs entirely 

 from the other locality in geological structure. 



The species of fishes in the nnetalliferous schists of Mans- 

 feld, Thuringia, &c., are not numerous, though the ichthyolites 

 are so abundant. They are referred to the following genera : — 



1. Pal^oniscum. Species, P. Freieslebense. De Blain. 

 M. de Blainville thinks that this impression, from Eisleben 

 and Mansfeld, should form a distinct genus, probably ap- 

 proximating to the sturgeons. This fish has the form of a 

 small dolphin in the anterior part of the body and head. It 

 is evidently abdominal. The pelvian fins are very near the 

 anus. There is but a single dorsal fin, very large, intermediate 

 to the central and anal, and raised on a sort of pedicle, like 

 that of the sturgeon's. The tail is short, but very broad, and 

 terminated by a very large fin, the upper lobe of which, longer 

 than the lower, appears to have been furnished with scales. 

 The radii of all these fins are very numerous, fine, and not 

 divided, as is the case with the sturgeons. 



2. Pal^othrissum. Under this generic name, M. de 

 Blainville includes several species of fish found in great 

 abundance in these schists, and hitherto found nowhere else. 

 The essential characters are — abdominal, malacopterygian, or 

 soft finned ; a single upper fin situated before the anal, and 

 between it and the pelvian fins ; bifurcated tail, the upper lobe 

 of which is usually much longer than the lower, and covered 

 with scales in all its upper half. 



P. macrocephalutn, De Blain. This species is evidently 

 abdominal ; has but a single dorsal fin, intermediate to the 

 ventral and anal. Tail bifurcated, and the two lobes nearly 

 equal. The head is very thick. 



P. magnum, De Blain. This ichthyolite is eighteen inches 

 long ; in other respects it differs little from the preceding. 



P. incequilohum, De Blain. A small species ; the remains 

 of which, more or less complete, indicate a fish about six 



