Fig. 211.—Melanocetus johnsonii.
Two species are known from the Atlantic: M. bispinossus and M. johnsonii, obtained at depths of from 360 to 1800 fathoms. The specimen figured was not quite four inches long, and contained in its stomach, rolled up spirally into a ball, a Scopeline fish which measured 7½ inches in length and one inch in depth.
Oneirodes.—A deep-sea fish from the Arctic Ocean, differing from the preceding in possessing a second isolated dorsal ray on the back.
Antennarius.—Head very large, high, compressed; cleft of the mouth vertical or subvertical, of moderate width. Jaws and palate armed with rasp-like teeth. Eye small. Body naked or covered with minute spines; generally with tentacles. The spinous dorsal is reduced to three isolated spines, the anterior of which is modified into a tentacle, situated above the snout. The soft dorsal of moderate length; anal short. Ventrals present.
The fishes of this genus are pelagic, frequently met with in mid-ocean between the tropics, especially in parts of the sea with floating vegetation; not rarely individuals are found far from their native latitudes, carried by currents to the coasts of Norway and New Zealand. Their power of swimming is most imperfect. When near the coast they conceal themselves between corals, stones, or fucus, holding on to the ground by means of their arm-like pectoral fins. Their coloration is so similar to their surroundings that it is hardly possible to distinguish the fish from a stone or coral overgrown with vegetation. Their way of attracting and seizing their prey is evidently the same as in the other fishes of this family. The extraordinary range of some of the species which inhabit the Atlantic as well as the Indo-Pacific Oceans, is the consequence of their habit of attaching themselves to floating objects. Almost all the species are highly coloured, but the pattern of the various colours varies exceedingly. These fishes do not attain to any considerable size, and probably never exceed a length of ten inches. A great number of species have been distinguished by ichthyologists, but probably not more than twenty are known at present. The species figured on p. 295 (A. caudomaculatus) is common in the Red Sea, and probably occurs in other parts of the Indian Ocean.
Brachionichthys and Saccarius are allied genera from South Australia, Tasmania, and New Zealand.
Chaunax.—Head very large, depressed; cleft of the mouth wide, subvertical; eye small; rasp-like teeth in the jaws and palate. Skin covered with minute spines. The spinous dorsal is reduced to a small tentacle above the snout; the soft dorsal of moderate length; anal short; ventrals present.
A deep-sea fish (Ch. pictus), of uniform pink colour; hitherto found near Madeira and the Fidji Islands, at a depth of 215 fathoms.
Malthe.—Anterior portion of the body very broad and depressed. The anterior part of the snout is produced into a more or less prominent process, beneath which there is a tentacle retractile into a cavity. Jaws and palate with villiform teeth. Skin with numerous conical protuberances. Soft dorsal fin and anal very short. Gill-opening superiorly in the axil; gills two and a half.
Although the rostral tentacle is situated at the lower side of the projection of the snout, it must be regarded as the homologue of a dorsal spine. In some of the preceding genera, Oneirodes and Chaunax, the first dorsal spine is so far advanced on the snout as to come into connection with the intermaxillary processes; and the position of the rostral tentacle in Malthe is only a still more advanced step towards the same special purpose for which the first dorsal spine is used in this family, viz. for the purpose of obtaining food. In Malthe it is obviously an organ of touch. This genus belongs to the American shores of the Atlantic; M. vespertilio being a tropical, M. cubifrons a northern species.