SYNOPSIS. 355 



C. U.—Cuv. f Val, iv. p. 327, pi. 87 ; Tarr. Brit. Fish., 



i. p. 87. Perca marina, Lhin., Perm. Brit. Zool., iii. p. 349, 



pi. 69. Scorpsena Norvegica, Northern Sebastes, Jmyns^ 



Brit. Vert., p. 347. 



Gen. XIII. Gasterosteus. Head smooth ; one dorsal fin, 



the place of the first dorsal being occupied with from three to 



fifteen spines ; ventral fin reduced to a single sprniform ray : 



body without scales, the sides protected by transverse plates, 



abdomen likewise defended by a triangular plate ; teeth in both 



jaws, none on the vomer or palatines. 



Sp. 26. G. trachv/rm. Rough-tailed Three-spined Stickle- 

 back. Dorsal spines three, the central one longest ; lateral 

 plates extending to the base of the tail ; ventral spine tri- 

 angular at the base ; tail with a slight ridge on each side* 

 Fin-rays, D. iii 9 : P. 10 : V. 1 : A. H-8 : C. 12.— Cuv. 

 <|- Val, iv, p. 481, pi. 98, fig. 1 ; Tarr. Brit. Fish., I 90. 

 G. aculeatus, Don. Brit. Fish., pi. 11. Tliree-spined Stickle- 

 back, Jenyns' Brit. Vert., p. 348. 

 Sp. 27. G. semiarmatus. Half-armed Stickleback. Dorsal 

 spines three, lateral plates not extending beyond the line 

 of the vent. Fin-rays, D. iii -f 1 : P. 1 : A. 1 -f- 9 : C. 12. 

 Cuv. d; Val, iv. p. 493 ; Yarr. Brit. Fish., i. 94. 

 Sp, 28. G. leiurus. Smooth-tailed Stickleback. Dorsal spines 

 as in the two last species ; lateral plates not extending 

 beyond the second dorsal spine, the side beyond that 

 smooth and soft. Fin-rays, D. iii. -|-10:P. 11:A. l-}-8: 

 C, 12.— CW. & Val, iv. p. 481, pi. 98, fig. 4 ; Tarr. Brit. 

 Fish., i, 95. 

 Sp. 29. G. hrachycentrus. Short-spined Stickleback. Lateral 

 plates as in G. leiv/rus; dorsal spines three, very short. 

 Fin-rays, D. iii-|-13 : P. 10 : A. l-[-9 : C. \2.—Cuv. ^ 

 Val, iv. p. 499, pi. 98, fig. 2. 



Superior in size to L. leiv/rus^ and the vertebrae more 

 numerous. 

 Sp. 30. G. spirmlosus. Four-spined Stickleback. Dorsal spines 

 four; a single lateral plate behind the pectoral fin. Fin- 

 rays, D. iv + 8 : P. 9 : V. 1 : A. 1 + 8 : C. 12.— Yarr, 



