Table of Contents
The sea snails are tadpole-shaped, soft-bodied little fishes; and like the lumpfish (p. 459) most of them have a sucking disk on the chest, supported by the vestigial rays of the ventral fins. But the skin is smooth, and without tubercles, and the spiny and soft parts of the dorsal fin are continuous as a single fin. The more than 115 species that are known are widely distributed in Arctic, North Temperate, and Antarctic Seas, and from the intertidal zone down to 2,000 fathoms or so. The Gulf of Maine harbors two species. A third (Careproctus ranulus Goode and Beane, 1879) is known only from the vicinity of Halifax, Nova Scotia; from Middleground off eastern Nova Scotia, from the Grand Banks, and off southeastern Newfoundland; perhaps from the estuary of the St. Lawrence River, also.
We include it in the following Key, on the chance that it may be encountered in the deeper parts of our Gulf, sooner or later.
|KEY TO GULF OF MAINE SEA SNAILS|
|1.||The spiny (front) and soft (rear) portions of the dorsal fin are separated by a notch||—||Sea snail, p. 464|
|There is no notch between the spiny portion and the soft portion of the dorsal fin||2|
|2.||The anal fin has only about as many rays (26-29) as the pectoral fin (28-33); there are two separate nostrils; the body is opaque, variously striped or spotted||—||Striped Sea Snail, p. 466|
|The anal fin has many more rays (at least 48) than the pectoral (27-28); there is only a single nostril; the body is translucent in life and colorless||—||Careproctus ranulus|
 For a detailed description, with illustrations, see Goode and Bean, Smithson. Contrib. Knowl., vol. 30, 1895, p. 275, vol. 31, pl. 70, figs. 251-251a, 251b.
 Some species of the genera Paraliparis and Amitra have lost the sucking disk.
 See V. Burke (Bull. 150, U. S. Nat. Mus., 1930) for a study of the family as a whole, giving descriptions and geographic ranges of all known species.
 McKenzie and Homans, Proc. Nova Scotian Inst. Sci., vol. 19, 1938, p. 278.
 We cannot judge whether the Careproctus reported by Vladykov and Tremblay (Natural. Canad., vol. 62 (ser. 3, vol. 6), 1935, p. 81) from the estuary of the St. Lawrence River as C. longipinnis was indeed identical with the fish from north of the Faroe Islands that was described under that name by C. V. Burke (Ann. Mag. Nat. Hist. Ser. 8, vol. 9, 1912, p. 510), or whether it is referable to ranulus; as seems the more likely on geographic grounds.