COTTOIDEiE. 



43 



Colour. — The under surface is silvery-grey minutely spotted with dark brown : on the sides 

 the dots are intermingled with crowded irregular blotches of the same colour, and on the back 

 and top of the head the colour is dark brown, nearly uniform, few spots of the light colour 

 appearing. 



Dimensions. C. cognatus. C. gobio. 





[riches. 



Lines. 



Inches. 



Lines 



Total length including caudal fin . 



4 







4 







Distance between tip of muzzle and posterior edge of operculum 



1 



2 



1 



2 



„ „ orbit .... 







3* 







3* 



„ „ first dorsal 



1 



n 



1 



2* 



„ „ anus .... 



1 



ii 



1 



11 



Length of attachment of first dorsal . . . . . 







7h 







bh 



„ „ second dorsal .... 



1 



3 



1 





„ longest rays of pectorals . . . . . 







10J 







lOf 



,, ventrals ..... 







7 







7 



,. „ caudal ...... 







8£ 







8| 



,, „ first dorsal .... 







<H 







3* 



„ „ second dorsal . 







6| 







4| 



„ „ anal ...... 







5* 







4| 



Some individuals of C. cognatus, which are full of roe, measure only two and a half inches 

 of total length. All our specimens agree with each other in the number of rays in their fins. 

 There are four pretty long caeca round the pylorus, and the viscera correspond with the 

 description of those of C. gobio in the Histoire des Poissons. The stomach contained frag- 

 ments of dytisci, and of other fresh-water insects and crustacece, and also of some small fish. 



[12.] 2. Cottus polaris. (Sabine.) North Georgian Bull-head. 



Cottus polaris. Sabine, App. Parry's First Voyage, ccxiii. J. C. Ross, App. liii. 



This species is compared by Captain Sabine to C. gobio, but that has the head 

 almost unarmed. It agrees with C. claviger in the number of rays in the dorsals, 

 but its ventrals are described as having more rays than usual in this genus. 

 Captain J. C. Ross informs us that it seldom exceeds two inches in length, and 

 that it is very abundant on the east side of the peninsula of Boothia, affording a 

 plentiful supply of food to the numerous water-fowl which breed there. 



" Cottus capite spinis duabus, operculis spinis quatuor armatis^ 



" A species of Cottus, similar in habits to C. gobio, was very abundant on the shores of 

 North Georgia (lat. 75°), inhabiting the pools of water left by the tide, and the mouths of 

 small rivulets by which the snow on melting found its way to the sea ; the largest individual 

 did not equal two inches in length ; the head is more compressed and not so much flattened 

 as in the Cottus quadricornis, and is armed with two strong spines placed before and between 



G 2 



