THE CYPRINODONTS. 141 
length to the caudal. Head one and one half times the depth, two thirds as 
broad as long, flattened on the crown. Snout very broad, rounded in front, 
two thirds as long as the eye. Mouth wide, intermaxillary slightly protrac- 
tile, symphyses firm. Teeth simple, hooked, outer separated, larger, inner in 
bands, smaller, pharyngeal stouter, larger, a few stout with cusps ground off 
like molars. Eye large, two sevenths of the head, half of the interorbital 
space. Dorsal small, origin three fourths of the distance from the occiput to 
the base of the caudal, base its length farther back than that of anal. Anal 
larger, farther forward than dorsal. Ventrals very small, not reaching the 
vent, sometimes absent on one side. Pectoral elongate, pointed, nearly as 
long as the head, Caudal one and one half times the length of the head, or 
longer, median rays longest, acute pointed. Scales large. 
Brownish ; blackish at the lower edge of each flank and below the caudal 
pedicel. Black bands from the chin meet at the anal fin. Occasionally the 
entire lower surface is blackish. A broad dark band reaches up the sides 
behind the pectorals, another between the ventrals and the anal, and a third 
from the ventral surface to the base of the dorsal. A dark band from eye 
to eye around the chin; behind this a whitish streak. The dark color is on 
the centres of the scales, which produces the appearance of vittw. Fins 
brownish, clouded or banded, darker toward the ends, Top of snout lighter 
in color. The vertical bands grow fainter with age. In shape this species 
approaches Anableps. 
Jutahy. 
PTEROLEBIAS. 
In the species upon which this genus is founded the body is much com- 
pressed, the caudal section especially being deep, thin, and blade-like at the 
lower edge. A transsection of the middle of the head is a sub-quadrate. 
The snout is short and blunt, the chin steep, and the mouth has an oblique 
cleft, as in Orestias, The lower jaw is the more prominent, the upper is 
somewhat protractile, and the symphyses are firm. The teeth are small, 
subconical, in bands, and the pharyngeal have a shoulder. Gill openings 
wide; gill membranes short, partly united, free from the isthmus. Fins 
pointed; fin rays elongate. Dorsal short, its origin behind that of anal. 
Anal long. Pectorals and ventrals of medium size. Lateral line distinct. 
Body cavity nearly half the length of the body, without the caudal. 
The proper place for this genus is between Rivulus and Cynolebias. 
