WITH HARD CHEEKS. 



ACANTHOPTERYGIL WITH HARD CHEEKS. 



THE SHORT-SPINED STICKLEBACK. 



Gasterosteus bruchycentrus, Cuv. et VALENC. Hist. Nat. des Poiss. t. iv. p. 499, 

 pi. 98, fig. 2. 



SPECIMENS of a large species of Three-spined Stickleback, 

 with very short spines, taken in the North of Ireland, have been 

 supplied me by William Thompson, Esq. Vice-President of 

 the Belfast Natural History Society, who believes it to be 

 identical with Cuvier^s species as quoted above. In the number 

 of lateral plates, this species agrees with G. leiurus; but the fish 

 is of much larger size, while the spines, as may be seen by com- 

 parison, are very considerably shorter. The lateral plates do 

 not extend beyond the limits of the pectoral fin, from whence 

 the lateral line is a mere linear depression ; and whether the 

 examples of this fish be taken from mountain streams, those 

 of the lower grounds, or from the sea, the water of the lowest 

 temperature produced specimens of the largest size. Accord- 

 ing to Mr. Thompson, the vertebrae in this species are more 

 numerous than in G. leiurus. The plate represents this fish 

 of the natural size. Fin-rays : 



D. Ill -f 13 : P. 10 : A. 1 + 9 : C. 12. 



