GASTEROSTEIM). 239 



p. 94 (Ed. 3) ii, p. 82 ; Parnell, Fishes Firth of Forth, p. 30, pi. xxv, and Wern. 

 Mem. vii, p. 192, pi. xxv; Blanchard, Poiss. Eaux Douces, France, p. 224, c. fig. ; 

 Sauvage, Epin. p. 15. 



The half -armed stickleback. 



In this variety the vertical scaly plates from ten to fifteen in number extend 

 from the head along the side half way to the base of the caudal fin ; the 

 lateral-line may have a slightly raised keel near the tail. The example figured 

 life size I captured, assisted by Mr. Lonie, in a rock pool at St. Andrew's, along 

 with the first variety. 



Variety 4. Gasterosteus gymnurus, Plate LXVI1I, fig. 3. 



Cuv. Regne Anim. Gasterosteus leiurus, Cuv. and Val. iv, p. 481, pi. xcviii, 

 f. 4 ; Yarrell, Ann. and Mag. N. H. iii, p. 522, and British Fish. (Ed. 1) i, p. 81, 

 c. fig. ; (Ed. 2) i, p. 95 (Ed. 3) ii, p. 83 ; Parnell, Fish. Firth of Forth, p. 30, 

 pi. xxv and Wern. Mem. vii, p. 190, pi. xxv ; Nilss. Skan. Fauna, Fiske, 

 p. 105 ; Coste, Mem. Sci. Sav. Etrang. x, 1848 ; Giinther, Neckarfische, p. 29 ; 

 Warrington An. and Mag. N. H. (2) 1855, xvi, p. 330 ; Blanchard, Poiss. France, 

 p. 225, c. fig.; Steind. Sitz. Ak. Wiss. Wien, 1865, Nov. 3rd; Sauvage, Epin. 

 p. 16. 



Gasterosteus dimidiatus, Reinb. Kgl. D. Vid. Selsk. Nat. Mat. Afh. B. 7, p. 104, 

 og. 193. 



The quarter-armed or smooth-tailed stickleback. 



In this variety the vertical scaly plates, from four to six in number, extend 

 from the head as far as the end of the pectoral fin, and this is the most common 

 inland form in Great Britain and Ireland. The example figured life size I took 

 at Edgeworthstown along with examples of varieties brachycentrus and spinulosus. 



Variety 5. Gasterosteus brachycentrus. 



Cuv. and Val. iv, p. 499, pi. xcviii, f . 2 ; Thompson, Nat. Hist. Ireland, iv r 

 pp. 82, 85, 88 ; Yarrell, Brit. Fishes (Ed. 1), i, p. 82, c. fig. (Ed. 2) i, p. 96 (Ed. 

 3) ii. p. 88 ; Nilss. Skan. Fauna, Fiske, p. 106 ; Heckel and Kner, Siissw. f. 17 ; 

 Giinther, Catal. i, p. 5 ; Steind. Catal. Pre. Poiss. Port. Suite, p. 1 ; Sauv. Epin. 

 p. 23 ; Houghton, British Fresh-water Fishes, p. 14, c. fig. 



Leiurus brachycentrus, Swainson, Fishes, ii, p. 242. 



The short- seined stickleback. 



In this variety the dorsal and ventral spines are very short, and the vertical 

 scaly plates, from four to six in number, extend along the side from the head to 

 the end of the pectoral fin. 



I took two examples at Edgeworthstown among a number of the varieties G. 

 gywmurus and spinulosus. 



Variety 6. Gasterosteus spinulosus. 



Jenyns, Manual, p. 350 ; Stark, Jamieson's Edin. Journ. 1830, p. 327 ; Yarrell, 

 Brit. Fishes (Ed. 1) i, p. 83, c. fig. (Ed. 2) i, p. 97 (Ed. 3) ii, p. 89 ; Thompson, 

 Nat. Hist. Ireland, iv, p. 88 ; Parnell, Fishes Firth of Forth, p. 36, t. xxv, and 

 Wern. Mem. vii, p. 196, t. xxv ; Nilss. Skan. Fauna, Fiske, p. 106 ; White, Catal. 

 p. 36 ; Giinther, Catal. i, p. 5 ; Sauvage, Epin. p. 25. 



Leiurus spinulosus, Swainson, Fishes, ii, p. 242. 



Four-spined stickleback. 



The extra spine is very short and situated between the normal last but one, 

 and last : none of the spines serrated : the pubic plate long and narrower than in 

 G. aculeatus of a similar size. None of Jenyns's examples exceeded If inches in 

 length, and, as he observes, " possibly a mere variety of the last species, which 

 is said to have been numerous in the same pond." Thompson (Nat. Hist. Ireland, 

 iv, p. 88) observes upon possessing from near Portarlington, Queen's County, a 



