Dorsal spines nine or ten.
* It is more than probable that some of the other foreign Gasterostei described by Cuvier are mere varieties of this species. They hardly differ more from those described above than these last do from each other.
G. Pungitius, Linn. Syst. Nat. torn. i. p. 491. Block, Ichth. pl. 53. f. 4. Don. Brit. Fish. vol. ii. pl. 32. Flem. Brit. An. p. 219. Lesser Stickleback, Will. Hist. Pise. p. 342. Ten-spined Stickleback, Penn. Brit. Zool. vol. iii. p. 262. pl. 50. no. 130. Id. (Edit. 1812). vol. iii. p. 355. pl. 61. Yarr. Brit. Fish. vol. i. p. 85. L'Epinochette, Cuv. et Val. Poiss. torn. iv. p. 370. Cuv. Reg. An. torn. ii. p. 170.
Rarely exceeding two inches.
(Form). Rather more elongated than the G. aculeatus; the depth not so great: differs essentially from that species in wanting the lateral scaly plates, although it possesses the triangular one on the belly, and the ascending branch from the base of the ventral spines: dorsal spines generally nine, but sometimes ten in number, much shorter than in the G. aculeatus, all equal, placed at equal distances from each other, erect but somewhat inclining alternately to the right and to the left, without denticulations at the edges, each furnished with a small membrane at the base: ventral spines barely so long as the ventral plate, likewise without serratures: ventral plate somewhat narrower and more pointed than in the G. aculeatus: sides of the tail keeled; each keel being furnished with several slender scales, which themselves appear keeled under the microscope:
D. 9 or 10 - 10 or 9; A. 1/9; C. 12; P. 10; V. 1/1.
(Colours). Back and portion of the sides yellowish green, marked occasionally with transverse dusky bands; abdomen silvery; the whole more or less dotted with black specks: fins pale. A variety sometimes occurs of a uniform dark bluish black, pervading the whole body above and below.
Var.β . G. lsevis, Cuv. Reg. An. vol. ii. p. 170. Sides of the tail smooth.
Equally abundant with the G. aculeatus, and as generally distributed. Like that species, is occasionally found in salt water. Habits similar. Obs. The G. Icevis of Cuvier differs in no respect excepting in wanting the carinated scales at the sides of the tail, and is evidently a mere variety.
(2. Spinachia, Flem).