24 HISTORY OF THE FISHES OF MASSACHUSETTS. 



The fin rajs are as follows :— D. 2-4- 1 - 8. P. 30-6. V. 1-4. A. 6. 

 C. 10t. Length about 6 inches. 



Remarks. The accompanying description and figure are prepared from a specimen 

 sent me by Dr. Yale from Holmes's Hole ; it is the only individual I have seen. 



This species was very well described by Dr. Mitchill in his supplement to his fishes 

 in " The American Monthly Magazine and Critical Review," and still better by Dekay 

 in his New York Report. 



Newfoundland, Cuvier. Massachusetts, Storer. Connecticut, Linsley. New 

 York, Mitchill, Dekay. Gulf of Mexico, Parra. Caribbean Sea, Cuvier, Schomburgk. 



GENUS III. COTTUS,* Aktedi. 



Inhabiting only fresh water. But one small spine at the angle of preoperculum ; 

 sometimes another still smaller, always hidden under the skin and perceptible to the 

 touch only, at the lower margin of the suboperculum. Head very depressed, more 

 or less truncated in front, generally broader than high, but always very uniform, being 

 scarcely detached from the body unless by its more considerable breadth. Second 

 dorsal always higher than first. Ventrals with three or four soft rays. Lateral line 

 usually interrupted. 



Cottus gracilis, Heckel. 

 The River Bull-head. 



(Plate IV. Fig. 3.) 



Vranidea quiescens, Little Star-gazer, Dekat's Report, p. 61, pi. v. fig. 914. 

 Cottus gobio, Ayres, Bost. Journ. Nat. Hist., v. p. 121, pi. xi. 



" " Storer, Synopsis, p. 52. 



Cottus gracilis, Heck., Girard, Proceedings of Bost. Soc. Nat. Hist., HI. p. 189. 



Color. Light green mottled with irregular dark-brown blotches, which are larger 

 on the posterior part of the body. 



Description. Length of the head about one fifth that of the body ; much broader 

 than the body; flattened above back of the eyes. Preoperculum armed at its posterior 

 superior angle with a sharp spine curving upwards, and below this upon its edge 



* The genus Cottus has heretofore been composed of two separate groups, consisting of fluviatile and 

 marine species. Mr. Girard, after having devoted much attention to the subject, has formed from these two 

 distinct genera, and gives as his reason for not accepting Dekay's Uranidea, that, according to the principles 

 of nomenclature, Cottus must be retained for the fresh-water group, having been at first applied to them. It 

 remains, however, to be seen whether these changes will be accepted by succeeding ichthyologists. 



