XXI OSTARIOPHYSI 575 
Mouth usually more or less protractile, toothless ; lower pharyngeal bones 
large, faleciform ; body naked or scaly ; no adipose dorsal fin 
3. Cyprinidae. 
II. Parietal bones usually fused with the supraoccipital ; symplectic 
absent ; body naked or with bony scutes; mouth usually toothed, with 
barbels ; adipose fin often present. 
Ribs attached to strong parapophyses ; operculum well developed 
4. Siluridae. 
Ribs sessile ; parapophyses absent; operculum more or less developed ; 
mouth inferior. 2 : : : ; . 5, Loricarvidae. 
Ribs sessile ; strong parapophyses to the vertebrae ; operculum absent 
6. Aspredinidae. 
Fam. 1. Characinidae. — Mouth non-protractile, usually 
bordered by the praemaxillaries and the maxillaries, rarely by 
the praemaxillaries only; jaws usually toothed. Parietal bones 
united in a sagittal suture or separated by a fontanelle ; opercular 
bones well developed; symplectic present. Pharyngeal bones 
normal, with small teeth. Ribs mostly sessile; no parapophyses 
in the thoracic region; epipleurals and epineurals, mostly free 
floating. Pectoral fins inserted very low down, folding like the 
ventrals. Body covered with scales. An adipose dorsal fin 
often present. 
This is a very generalised type, although perhaps not directly 
derived from the bony Ganoids, as believed by Sagemehl. The 
species number about 500, and are confined to the freshwaters 
of Africa and Central and South America. The classification of 
the family is still in an unsatisfactory state, but the division into 
the following groups (hardly deserving the rank of sub-families), 
although quite provisional, appears preferable to the highly arti- 
ficial arrangement hitherto adopted :— 
I. No adipose fin. 
A. ERYTHRININAE.—Carnivorous; teeth strong; maxillary large; gill- 
openings wide; scales cycloid. American: Macrodon, Erythrinus, 
Lehiasina, Pyrrhulina, Corynopoma. 
II. Adipose fin usually present. 
B. HyprocyontnarE.—Entirely or partially carnivorous; teeth strong ; 
maxillary well developed ; scales cycloid ; lateral line usually nearer 
ventral than dorsal outline (sometimes only on the tail), African: 
Sarcodaces, Hydrocyon, Bryconaethiops, Alestes, Micralestes, Petersius, 
American: Acestrorhynchus, Boulengerella, Acestrorhamphus, Crenu- 
chus, Chalceus, Brycon, Bryconops, Bryconodon, Creagrutus, Chaleinus, 
Brachychalcinus, Pseudocorynopoma, Stichonodon, Gastropelecus, Tetra- 
gonopterus, Scissor, Chirodon, Prabucina, Iquanodectes, Aphiocharaz, 
Salminus, Oligosarcus, Agoniates, Paragoniates, Leptagoniates, Anacyrtus. 
