178 FISHES OF WESTERN SOUTH AMERICA 
4mm., eye 3 mm., height of dorsal 7 mm., dorsal spine 6 mm., pectoral spine 7 mm., 
pectoral ray 8 mm., ventral 6 mm., upper caudal lobe 10 mm.; plates 23 above, 20 
below, fontanel short, not reaching base of occipital process. 
D. I, 7.5; A. I, 6.5; base of dorsal equal to its distance from the tip of the 
adipose; barbel not reaching gill opening; lower lip only slightly prolonged into an 
acute barbel-like tip; length before and behind dorsal spine the same; depth 2.4; 
adipose spine short and conical, equal to eye; caudal peduncle equal to length of 
snout; snout short, less than double the postorbital space, tending to be vertical, 
frontal elevated and convex; eye 1.7 in snout; anal slightly notched into ventral 
contour; pectoral reaching to last third or fourth of ventral; humeral plates narrow 
and widely separated entire length. 
A dark spot on tip of dorsal, a line along the spine, a line along the margin of 
the fin, and the penultimate dorsal ray dark; adipose fin dusky behind the spine 
and in a submarginal band; six narrow dark lines across the caudal fin and its 
lobes; one or two similar lines across the anal; in the type a conspicuous black band 
(hooked in front) along the middle of the sides in a much wider colorless band; 
each scale above and below the band with a black vertical line; a black line along 
the base of dorsal fin; head with asymmetric vermiculating lines. In the paratypes 
the dark median line fades anteriorly, the vertical lines tending to break up into 
spots. 
157. CoRYDORAS LEUCOMELAS Eigenmann and Allen, sp. nov. 
Plate XII, fig. 4 
15818, 1, 39 mm., type, Yarinacocha, Allen, September, 1920. 
Head 3; depth 2.5; D. I, 7.5; A. I, 6.5; plates 23 above, 20 below; interorbital 
2.25 in the head; snout twice as long as the postorbital part of the head; dorsal 
contour of the head only moderately convex; eye 3.3 in the head; fontanel not 
reaching the base of the occipital process, which is oval and as long as broad; barbels 
just reaching the vertical from the anterior margin of the eye; mental barbels but 
slightly bifid; suborbital reaching about one fourth to the upper lip; dorsal spine 
greater than snout and eye; length before and behind dorsal spine the same; base 
of dorsal greater than its distance from the adipose; an azygous plate in front of 
the adipose; adipose spine conical, decurved, sharp-pointed, slightly exceeding the 
eye in length; pectoral reaching past the middle of ventral fin; pectoral spine a little 
longer than the dorsal spine; anal spine 2.5 in the longest anal rays; caudal peduncle 
narrow and elevated, only slightly exceeding snout; humeral plates widely sepa- 
rated, short, and subacute behind. 
Dorsal mostly black, only the antepenultimate ray with its membranes and 
the tip of the preceding ray hyaline; caudal with two vertical bars and vertical 
series of spots, the first through the level of the tips of the middle rays; anal with 
a bar through its middle; sides with many spots, decreasing in size downward. 
Similar to C. punctatus in many respects; dorsal all dark except for the two 
penultimate rays and the tips of the two preceding; single azygous plate. 
