The “Torsk” (B. brosme) is confined to the northern parts of the temperate zone, and probably extends to the arctic circle.
Third Family—Ophidiidæ.
Body more or less elongate, naked, or scaly. Vertical fins generally united; no separate anterior dorsal or anal; dorsal occupying the greater portion of the back. Ventral fins rudimentary or absent, jugular. Gill-openings wide, the gill-membranes not attached to the isthmus.
Marine fishes (with the exception of Lucifuga), partly littoral, partly bathybial. They may be divided into five groups.
I. Ventral fins present, attached to the humeral arch: Brotulina.
Brotula.—Body elongate, covered with minute scales. Eye of moderate size. Each ventral reduced to a single filament, sometimes bifid at its extremity. Teeth villiform; snout with barbels. One pyloric appendage.
Five species of small size from the Tropical Atlantic and Indian Ocean.
Fig. 250.—Lucifuga dentata, from caves in Cuba.
Lucifuga are Brotula organised for a subterranean life. The eye is absent, or quite rudimentary, and covered by the skin; the barbels of Brotula are replaced by numerous minute ciliæ or tubercles. They inhabit the subterranean waters of caves in Cuba, and never come to the light.