FISHES. 



283 



_ The principal species of sticklebacks belong to three genera ; there are the two- 

 spined sticklebacks ( Gasterosteus), the largest American members of the family, having, 

 as the namfe indicates, two divergent spines on the back; the many-spined sticklebacks 

 (Pyffosteus), distinguished by the development of about six to ten divergent spines 

 on the back; and the little Apeltes quadracus, which has three free spines on the back, 

 but is more especially distinguished by the pelvic bones being widely separated and 

 extending along the sides, instead of being like a spear-head, and pointed at the middle 

 of the belly, as in the other species. 



The largest of all the sticklebacks, and an exclusively salt-water fish, is the Spina- 

 chia spinachia or vulgaris, the many-spined stickleback. It is readily distinguishable 

 by its slender form, tubiform snout, much elongated tail, and numerous dorsal spines. 

 It is confined to the eastern side of the north Atlantic. 



Fig. 157. — Fistularia tabaccaria, tobacco-pipe fish. 



A family nearly related to the Gasterosteids is that of the Attloehtnchid^, 

 distinguished by the snout being elongated and tube-like, the development of four 

 rays besides the spine to each ventral, and of four branchiostegal rays. Two species, 

 representing two genera, are the only known species ; both are inhabitants of the 

 north Pacific, and resemble considerably the Spinachia of Europe, but have a still 

 more tubiform snout. 



The name Fistulaeiid^ is given as a family designation for Hemibi-anchs with 

 the first four vertebrae very much elongated, a very long and somewhat depressed 

 body, a long tubiform snout, and ventrals arising near the middle of the length, and 

 having five or six rays each, but no spines; they are also destitute of dorsal spines. 

 The two median rays of the caudal fin are united together and form a long filament 

 extending backwai'ds. The species are chiefly known under the name tobacco-pipe 

 fishes; a couple of them occasionally visit the coasts of the United States, but they 



