FOSSIL FISH. 399 



Herring (ClupcBo), Sp. C. sprattiformisy De Blain. This 

 is the most common species, and evidently belonging to this 

 genus. The impression indicates a small abdominal fish, from 

 four to five inches long. The head is moderate, the eyes large, 

 the opercle very much cleft ; the radii of the pectoral fins, ten 

 in number, are very fine. The pelvian fins are attached about 

 the middle of the length of the body, have fourteen or fifteen 

 radii, and at their base a sort of long scale, as in certain her- 

 rings. The dorsal fin is single, and opposed to the pelvian ; it 

 is small, and has ten or a dozen radii. The anal fin, equally 

 small, and having nearly ten radii, is in the middle of the 

 space which separates the ventrals from the caudal. The tail 

 is terminated by a fin with very fine radii, and deeply bifur- 

 cated. 



C dubia, De Blain. Pretty evidently belonging to the same 

 genus, but a little larger than the preceding. 



C. Knorrii, De Blain. A wonderfully perfect impression. 

 The principal difference between it and the foregoing is in the 

 more backward position of the dorsal fin ; which, instead of 

 corresponding with the pelvian fins, occupies the space between 

 them and the anal. 



C. elongata, De Blain. Distinguished from the preceding 

 species by a more elongated form. The dorsal fin appears to 

 be exactly opposed to the anal. 



C. Davilei, De Blain. The remains of this fish indicate a 

 form rather short and thick. The head, moderate, has no 

 scales. The pieces of the opercle are very large, and so is its 

 aperture. The branchiostegous rays are rather slender, and 

 from seven to nine in number. The vertebrae are very short, 

 and consequently numerous. M. de Blainville counted sixty- 

 four. The abdominal cavity is long, and formed by a great 

 number of tolerably fine ribs. The pectoral fins are pretty 

 large, and placed very low. The pelvian or ventral are in the 

 middle of the abdomen, and have nine rays. The dorsal fin is 

 large, arched towards the back, commencing much before the 



