31 ♦U 
B2tllctin ^ 7 , United States N^ational Museum. 
ventrals; bead long, pf>inted, its dorsal contour straight from tip of 
snout to a point a little posterior to the eye, where it curves upward; 
interorbital space Hat; eye high up, nearer tip of snout than edge of 
ojtercle hy a distance about equal to diameter of jmpil; width of j)re- 
orbital space equal to diameter of pupil; mouth oblique, the cleft extend- 
ing downward to a point opposite lower edge of pupil ; lips growing more 
Heshy posteriorly, the lower forming a fold across the u])per at their junc- 
tion; distal end of maxillary angular, extending almost to a vertical from 
anterior edge of orbit; lower jaw very long, luojecting beyond upi)er a 
distance equal to diameter of pupil; viewed from above, both jaws are a 
little more pointed than are those of C. estor or of C. humboldtiauum. 
Teeth on jaws in bands, minute, projecting backward; no teeth on vomer 
or ])alatiues; gill-rakers slender, close together, length of longest c(iual to 
diameter of pupil; vertebra* t4. A rather indefinite lateral line extend- 
ing along body, 10 scales Itelow the first dorsal, the pores absent on many 
of the scales; scales crenate, growing smaller dorsally, larger ventrally, 
those on posterior part of occiput, on nape, on region anterior to ]>ec- 
torals — above and below, and on base of caudal, very small and crowded 
together, those in the region of dorsals not reduced in size or crowded 
except at insertion of fins, where there are 4 very small ones; cheek 
with 5 rows; lower jaw and uj)per part of snout naked; basal half of inter- 
radial membranes of caudal with minute scales; first 3 spines of dorsal 
highest, extending when depressed within half their length of origin of 
soft dorsal ; first dorsal ray preceded by a shorter, simjjle, closely attached 
one; other rays successively shorter than first; edge of fin slightly con- 
cave; anal similar to soft dorsal in shape, its basis ly times as long as that ^ 
of soft dorsal; attachment of first ray under a point half way between 
insertions of dorsals; caudal deeply forked, the lobes ffciual; i»ectoral 
pointed when depressed, uiijier rays longest, extending to a vertical half 
way between insertions of first dorsal and ventrals. Body, <luring life, 
almost translucent, with a bluish tinge of color; in alcohol, the color is a 
light olive yellow; a silvery lateral band extending from axil to base of 
caudal, the baud wider and brighter in color between dorsal and anal, 
growing narrow on caudal peduncle and then widening again at its ]»os- 
terior end. Head and body above, and the lower jaw, dusky; up]>er part 
of eye dark; edge of scales above lateral baud with small black dots; 
caudal somewhat dusky on its basal third; other fins with little or no dark 
color. 
Chirostoma ocoilane is easily distinguished from all other known s])ecies 
of the genus by its excessivelj* long lower jaw. Except the jaw and some- 
what larger eye it resembles C. estor in general aiq)earance. Laguna de 
Chapala, Mexico. (.Jordan A Snyder.) 
Known only from Laguna de Chapala, near Ocotlau, Mexico. (Tyjie, 
No. 6160, L. S. Jr. Uuiv. Mus. Coll. J. < >. Snyder.) 
Chirostoma ocotlane, Jokda.v & SXVOEU, Hull. U. .S. Fish C'oiu. 1S99 (1900), 141, Laguna 
de Chapala, near Ocotlan, Mexico. 
