XXIII ACANTHOPTERYGII ORF 
being possessed of an open duct to the air-bladder. About twelve 
species are known, referable to four genera: Pempheris, Parapria- 
canthus, Neopempheris, from the Indian, Pacific, and tropical 
Atlantic Oceans, and the deep-sea Lathyclupea, from the Indian 
aud Caribbean Seas, at depths of 145 to 419 fathoms. 
Fia. 402.—Pempheris muelleri. (After Jordan and Evermann.) 
Fam. 4. Centrarchidae.—No subocular lamina of the sub- 
orbitals, or subocular shelf; entopterygoid present; palate toothed; 
teeth conical. Praecaudal vertebrae with transverse processes 
from the third or fourth to the last; ribs mostly sessile, behind 
the transverse processes. Two nostrils on each side. Gill-mem- 
branes free from isthmus; 5 to 7 branchiostegal rays; gills 4, 
aslit behind the fourth; pseudobranchiae more or less developed, 
often rudimentary or absent. Lower pharyngeal bones separate. 
Soft portion of dorsal fin not more developed than the anal. 
Carnivorous freshwater fishes, some entering brackish water. 
Many are known to build nests. Mostly inhabitants of North 
America, the best known being the Sun-Fishes (Lepomis), and 
Black Bass (Vicropterus), several species of which have recently 
been introduced into continental Europe. Principal genera: 
Pomoxys, Centrarchus, Ambloplites, Chaenobryttus, Micropterus, 
Lepomis, Elassoma, Kuhlia. Thirty-two species are known. 
Fam. 5. Cyphosidae.—Herbivorous fishes, agreeing in their 
essential osteological characters with the preceding, differing in 
the incisor-like outer teeth and densely-scaled fins. Some 14 
species are known,from the Pacific and Indian Oceans, referable to 4 
genera: Cyphosus (Pimelepterus), Hermosilla, Sectator, Medialuna. 
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