XXII CATOSTEOMI 621 
larger fifteen-spined Stickleback (Spinachia vulgaris) 1s entirely 
marine; its nests are to be found on our coasts in sheltered rock- 
pools, and they are made chiefly of sea-weeds and Hydrozoa. 
Sticklebacks are short-lived, and are believed to breed only once. 
The Gastrosteidae are restricted to the northern hemisphere, 
being more abundant in the higher latitudes, extending to Ice- 
land, Greenland, and Bering Straits; the southernmost points 
of their distribution are Algeria in the Old World, and Lower 
California in the New.' 
A very large number of species have been described, but 
probably only about a dozen deserve to stand. 
Fic. 385.—Distribution of the Gastrosteidae. 
Fam. 3. Aulorhynchidae—The genera Aulorhynchus, and 
Auliseus, each with one species from the Northern Pacific, much 
resemble Spinachia in outward form and in the equal size of the 
anterior vertebrae, but the snout is still more produced, tubiform, 
and the ventral fins are formed of one spine and four soft rays. 
The difference which justifies their separation as a distinct family 
resides in the disposition of the ribs, which are flattened and 
ankylosed to the lateral bony shields. 
Fam. 4. Protosyngnathidae.— This family appears to be 
intermediate between the Gastrosteidae and the Aulostomatidae, 
agreeing with the former in possessing slender, free ribs, with 
the latter in having the first vertebrae elongate, though to a 
1 Dr. Sauvage has described a Gastrosteus texanus, but the locality is probably 
incorrect, as recent American works do not mention the occurrence of Sticklebacks 
in Texas. 
