I. Gill-opening in or behind lower axil of pectoral; mouth large, terminal or directed upwards.
Pectoral fin scarcely geniculated; ventrals present .......... 1. Lophiidae.
Pectoral fin scarcely geniculated; ventrals absent .......... 2. Ceratiidae.
Pectoral fin strongly geniculated; ventrals present .......... 3. Antennariidae.
II. Gill-opening behind lower axil of pectoral; mouth large, inferior; ventrals absent .......... 4. Gigantactinidae.
III. Gill-opening above axil of pectoral; mouth rather small, subterminal or inferior; pectoral fin strongly geniculated; ventrals present; spinous dorsal absent or reduced to a small tentacle lodged in a cavity under the snout .......... 5. Malthidae.
Fam. 1. Lophiidae.—Mouth extremely large, terminal, with very strong cardiform teeth. Gill-opening in lower axil of pectoral; pseudobranchiae present. Pectoral fin scarcely geniculated, with two pterygials. Ventral fin with 1 spine and 5 branched rays. Spinous dorsal present. Skin naked.
Twelve species, referable to three genera (Lophius, Chirolophius, and Lophiomus) living on the bottom of the Atlantic, Indian, and Pacific Oceans, at moderate or great depths. Lophius was represented in the Upper Eocene of Monte Bolca.
Fig. 434.—Chirolophius naresii. (After Günther.) × ⅓.