198 FISHES OF THE FIRTH OF FORTH. 



slightly concave ; ventral spine placed under the middle of the pec- 

 torals, not as long- as the abdominal plate ; lateral line commencing 

 over the scapular plate, and taking a straight course to the base of 

 the tail ; ascending portion of the pelvic plate rather narrow, not 

 extending so high as to meet the lateral line ; sides marked by a 

 number of linear transverse depressions, forming an angle at their 

 junction with the lateral line. Teeth small and fine in both jaws, 

 none on the vomer or palatines ; number of fin rays — 

 D. 10 ; P. 11 ; A. 10 ; V. 2 ; C. 12 ; Branchial rays 3. 



This fish is said to be equally abundant with the three- 

 spine species of stickleback, and is found in salt, as well as 

 in fresh water pools. In the district of the Firth of Forth, 

 I have met with but four specimens, and those were taken 

 in a small stream west of Frestonpans ; two of them dif- 

 fered in the number of dorsal spines, the one possessing 

 eleven spines and the other nine, — but in other respects they 

 were similar to those with ten spines. (See Plate XXVI.) 



Gasteuosteus spinachia.* — The Fifteen-spined 

 Stickleback. 



Specific Characters. — Back armed with fifteen spines. (PL XXVI.) 

 Description. — From a specimen five inches in length. Body much 

 elongated, rounded in front of the dorsal fin, behind it depressed ; 

 base of the tail compressed ; dorsal and anal fins of equal size, of a 

 triangular form, slightly rounded at their free margins ; caudal fin, 

 when expanded, slightly rounded at the end ; scapular plate, oper- 

 culum, and preoperculum, also rounded. Colour of the head, back, 

 and sides, brownish-yellow, occasionally bright-green ; cheeks, thorax, 

 and abdomen silvery- white ; anterior part of the dorsal and anal fins 

 black, the remainder transparent ; sides spotted and marked with ir- 

 regular brown bands, passing across the lateral line in the region of 

 the dorsal and anal fins ; a bright silvery band extending from the 

 angle of the mouth, round the inferior margin of the orbit, to the up- 

 per half of the preoperculum. Lateral line strongly marked, much 

 elevated, commencing over the operculum, and passing nearly in a 

 straight line to the base of the tail, composed of a number of imbricated 



* Gasterosteus spinachia, Cuv., Yarr., Jen., Linn., Bloch, Don. Spina- 

 chia vulgaris, Flem. Fifteen-spined Stickleback, Great Sea-adder, Bismore, 

 Duckins at Berwick, 



