Fig. 218.—Cyclopterus lumpus. a, Ventral disk.
Three species of “Lump-suckers” are known from the northern temperate and the arctic zones. The common North European and North American species, C. lumpus, is known also by the names of “Cock- and Hen-Paddle.” It attains to a length of twenty-four inches, but generally is much smaller. It is difficult to remove it from any object to which it once has attached itself by means of its sucking-disk. Its skin is so thick as to more or less entirely conceal the first dorsal fin; it is covered with rough tubercles, the larger ones being arranged in four series along each side of the body. In young specimens these tubercles are absent. The arctic species, C. spinosus, has large conical plates on the head and body, each plate with a spine in the centre. Also of this species the young are naked, the plates making only gradually their appearance, in the form of groups of tubercles. Their development is irregular, as young specimens of the same size may be entirely naked or tubercular. This species ranges beyond the 81° lat. N.
Fig. 219.—Young of Cyclopterus spinosus, from the Arctic Ocean, natural size.
Liparis.—Body sub-cylindrical, enveloped in a more or less loose naked skin; head broad, obtuse. The infraorbital bone is styliform posteriorly, extending backwards to the margin of the præoperculum. One dorsal fin, with feeble flexible rays. Villiform teeth in the jaws, none on the palate.
Small fishes from the northern coasts of the temperate zone, ranging beyond the arctic circle. Eight species are known, of which two (L. lineatus and L. montagui) occur on the British coasts.
Second Family—Gobiidæ.
Body elongate, naked or scaly. Teeth generally small, sometimes with canines. The spinous dorsal fin, or portion of the dorsal fin, is the less developed, and composed of flexible spines; anal similarly developed as the soft dorsal. Sometimes the ventrals are united into a disk. Gill-opening more or less narrow, the gill-membranes being attached to the isthmus.
Small carnivorous littoral fishes, many of which have become acclimatised in fresh water. They are very abundant with regard to species as well as individuals, and found on or near the coasts of all temperate and tropical regions. Geologically they appear first in the chalk.