Gymnomuræna differs from Muræna in having the fins reduced to a short rudiment near the end of the tail. Six species are known growing to a length of eight feet.
Fig. 307.—Gymnomuræna vittata, from Cuba.
Myroconger and Enchelycore belong to the same sub-family as Muræna, but the former is provided with pectoral fins, and in the latter the posterior nostril is a long slit, and not round as in the other genera.
FIFTH ORDER—LOPHOBRANCHII.
The gills are not laminated, but composed of small rounded lobes attached to the branchial arches. Gill-cover reduced to a large simple plate. Air-bladder simple, without pneumatic duct. A dermal skeleton composed of numerous pieces arranged in segments, replaces more or less soft integuments. Muscular system not much developed. Snout prolonged. Mouth terminal, small, toothless, formed as in Acanthopterygians.
Fig. 308.—Gills of Hippocampus abdominalis.
First Family—Solenostomidæ.
Gill-openings wide. Two dorsal fins, the rays of the anterior not articulated. All the other fins well developed.