164 ACANTHOPTERYGII, MAILED CHEEKS. 



back. Cuvier and Valenciennes assign nine spines 

 to this species, and Dr. Parnell lias found nine, ten, 

 and eleven, without any other marked difference. 

 It is a very small fish, not extending to an inch and 

 a half; it occurs not only in fresh water, but in 

 salt, and is thus one of the smallest fishes of the 

 ocean. It is not common in the Forth. It varies 

 a good deal in colour, ranging on the upper parts 

 from yellowish brown nearly to black, and beneath 

 being a dull white spotted with dark olive. 



(Sp. 32.) G. spinachia. The Fifteen-spined 

 Stickleback. (PI. VI.) We have already had occasion 

 to dwell somewhat largely on this fish, (see pp. 71, 

 74). It is the only remaining one of the British 

 species, and will be at once known by the most 

 casual observer, by its many spines, its prolonged 

 tail, and elongated snout, the under jaw being con- 

 siderably the longer. It is a salt-water fish, and is 

 sometimes called the Sea- adder ; it, however, does 

 not attain a greater length than six or seven inches. 

 It prevails in the northern seas, and is included in 

 the Fauna Orcadensis of Low. It is found in the 

 Cromarty Frith, is not common in the Forth, 

 abounds off the Berwickshire coasts, where its nest- 

 building tendencies have been narrowly watched, and 

 exists round the coasts, to the Land's-End. Regard- 

 ing the habits of this species Mr. Crouch supplied to 

 Mr. Yarrel the following notes: " It keeps near rocks 

 and stones clothed with sea-weeds, among which it 

 takes refuge upon any alarm. Though less active 

 than its brethren of the fresh water, it is scarcely 



