COTTOIDE.E. 41 



only under the pectorals ; six branchiostegous rays ; and teeth on the forepart of 

 the vomer, but none on the palate bones. The stomach is an obtuse sac, the pylo- 

 rus is surrounded by from four to eight cseca, the ovaries have a blackish colour, 

 and there is no air-bladder belonging to the fish of this genus. Platycephalic 

 differs from Cottus in having a still more depressed head, which is also differently 

 cuirassed, large abdominal ventrals of five rays, a row of sharp palatine teeth, seven 

 branchiostegous rays, and a scaly body. 



The Cottus which forms the subject of this article was taken in considerable 

 numbers in the clear waters of Great Bear Lake during the month of May, at 

 which period it resorts to the stony shallows to spawn. Specimens which we sent 

 to Baron Cuvier were returned with the remark, that they belonged to a species of 

 Cottus, and were " tres semblables aux C. gobio*," and they indeed correspond in 

 most particulars with the extended description of the latter in the Histoire des 

 Poissons. I have since compared these specimens minutely with an English gobio, 

 kindly lent to me by Mr. Yarrell, and the principal difference that I have been 

 able to detect in the American fish is the greater height of its dorsal and anal fins. 

 There is also a discrepancy in the number of the rays, but this can scarcely be 

 accounted a specific distinction, since different individuals of gobio show equally 

 extensive variations. The Bear Lake specimens having been long in spirits have 

 lost much of their colour., but the following particulars may still be noted. In 

 C. gobio the rays of the pectorals are variegated with rings alternately dark and 

 light ; in cognatus the colour is almost uniform, but varies in intensity in different 

 individuals. In one small female specimen of the latter, however, there is a slight 

 indication of these rings, and its body likewise is marbled in a more lively manner 

 than the rest, having a greater resemblance to gobio. The males are darker than 

 the females in the American as well as the European species. The specimen which 

 we have described in detail was the largest we obtained, and was selected for 

 description from its being exactly of the same length with the gobio with which it 

 was compared. 



DESCRIPTION 



Of a male specimen taken in Great Bear Lake, lat. 64J° N., May 26, 1825, and a comparison of it with an 



English C gobio. 



Form. — Head corresponding exactly with that of gobio in size and shape, except that the 

 mouth is rather larger : it forms one-third of the whole length excluding the caudal, and it is 



* Cuvier, speaking of C. minutus of Pallas from the sea of Ochotzk, says, " Sa ressemblance avec fesptce commune de 

 nos eaux douces est telle que nous n'oserions Pen distinguer," and I should have thought in a similar way of C. cognatus ; 

 but as Cuvier did not consider it to be the same with the common species, although greatly resembling it, it appears safer 

 to give it a distinct appellation. 



G 



