618 TELEOSTEI CHAP. 
Fam. 12. Amblyopsidae.—Mouth scarcely protractile, the 
maxillaries excluded from the oral border; teeth small, in jaws 
and palate, and on the pharyngeal bones. Praecaudal vertebrae 
with very strong parapophyses, bearing the ribs on their upper 
surface; epipleurals inserted on the ribs. Ventral fins rudi- 
mentary or absent. Vent jugular, close to the gill-clefts. 
Air-bladder present. 
Small ovoviviparous Fishes, closely related to, and evidently 
derived from, the Cyprinodontids, measuring from 1 to 5 inches, 
inhabiting ditches and small streams, or confined to subterranean 
waters of limestone caves, in the United States east of the Rocky 
Mountains. Six species, referable to three genera, are known. 
Fia. 376.—A, Chologaster cornutus, and B, Amblyopsis spelaea, nat. size. 
(After Jordan. ) 
In Chologaster, the eyes are well developed and the body is 
coloured. C. cornutus inhabits the lowland streams and swamps 
of the South Atlantic States, from Virginia to Florida; C. 
agassizit 18 found in the underground streams of Kentucky and 
Tennessee ; and C. papilliferus occurs under stones in the springs 
of south-western Illinois. Amblyopsis and Typhlichthys, which 
are evidently derived from the former, or from forms closely 
related to it, have the eyes rudimentary and more or less con- 
cealed under the skin, and the body is colourless. Amblyopsis 
spelaea is widely distributed in the caves east of the Mississippi, 
