Fig. 176.—Barracuda, Sphyræna barracuda Walbaum. Florida.
Sphyræna sphyræna is the spet, or sennet, a rather small barracuda common in southern Europe. Sphyræna borealis of our eastern coast is a similar but still feebler species rarely exceeding a foot in length. These and other small species are feeble folk as compared with the great barracuda (Sphyræna barracuda) of the West Indies, a robust savage fish, also known as picuda or becuna. Sphyræna commersoni of Polynesia is a similar large species, while numerous lesser ones occur through the tropical seas. On the California coast Sphyræna argentea is an excellent food-fish, slenderer than the great barracuda but reaching a length of five feet.
Several species of fossil barracuda occur in the Italian Eocene, Sphyræna bolcensis being the earliest.
Stephanoberycidæ.—We may append to the Percesoces, for want of a better place, a small family of the deep sea, its affinities at present unknown. The Stephanoberycidæ have the ventrals I, 5, subabdominal, a single dorsal without spine, and the scales cycloid, scarcely imbricated, each with one or two central spines. The mouth is large, with small teeth, the skull cavernous, as in the berycoids, from which group the normally formed ventrals abdominal in position would seem to exclude it. Stephanoberyx monæ and S. gilli are found at the depth of a mile and a half below the Gulf Stream. Boulenger first placed them with the Percesoces, but more recently suggests their relationship with the Haplomi. Perhaps, as supposed by Gill, they may prove to be degenerate berycoids in which the ventral fins have lost their normal connection.
Crossognathidæ.—A peculiar primitive group referred by Woodward to the Percesoces is the family of Crossognathidæ of the Cretaceous period. As in these fishes there are no fin-spines, they may be perhaps better placed with the Haplomi. The dorsal fin is long, without distinct spines, and the abdominal ventrals have six to eight rays. The mouth is small, with feeble teeth, and the body is elongate and compressed. Crossognathus sabandianum occurs in the Cretaceous of Switzerland and Germany, Syllæmus latifrons and other species in the Colorado Cretaceous, and Syllæmus anglicus in England. The Crossognathidæ have probably the lower pharyngeals separate, else they would be placed among the Synentognathi, a group attached by Woodward, not without reason, to the Percesoces.
Cobitopsidæ.—Near the Crossognathidæ may be placed the extinct Cobitopsidæ, Cobitopsis acuta being recorded from the Oligocene of Puy-de-Dôme in France. In this species there is a short dorsal fin of about seventeen rays, no teeth, and the well-developed ventral fins are not far in front of the anal. This little fish bears a strong resemblance to Ammodytes, but the affinities of the latter genus are certainly with the ophidioid fishes, while the real relationship of Cobitopsis is uncertain.
Fig. 177.—Cobitopsis acuta Gervais, restored. Oligocene of Puy-de-Dôme. (After Woodward.)
Suborder Rhegnopteri.—The threadfins (Polynemidæ) are allied to the mullets, but differ from them and from all other fishes in the structure of the pectoral fin and its basal bones, or actinosts.
