258 
BULLETIN or THE BUREAU OF FISHERIES 
Nino, Lake Zapotitan, ponds at El Angel, Lake Ilopango, small streams near San 
Salvador, Rio Lempa at Suchitoto and San Marcos, Rio San Miguel at San Miguel, 
and Lake Olomega. 
8. Genus PRIAPICHTHYS Regan 
Priapichthys Regan, Proc, Zobl. Soc. London, 1913, 991 (type Gambusia annedens Regan). 
Body elongate, head depressed above; mouth transverse; teeth in the jaws in 
narrow bands, the outer ones scarcely movable; dorsal fin in the adult male scarcely 
higher than in the female; intromittent organ greatly produced, longer than the 
head; alimentary canal not exceeding the length of the body and without convolu- 
tions. Two species, both apparently new, appear to belong to this genus. 
KEY TO THE SPECIES 
a. Dorsal fin in the female usually equidistant from the tip of snout and end of caudal, or slightly 
nearer the former; two branches of the median produced ray of the intromittent organ 
bearing spur-like hooks; median line of sides with a row of round black spots scarcely as 
large as the pupil, varying in number from 3 to 10 letonui, sp. nov., p. 258. 
aa. Dorsal fin in the female, usually an eye's diameter nearer the end of caudal than tip of snout; 
only one branch of the median produced ray of the intromittent organ with spur-like hooks; 
sides with 6 to 10 dark crossbars fosteri, sp. nov., p. 260. 
8. Priapichthys letonai sp. nov. 
Chimbola 
Type No. 87251, U.S.N.M.; male, length 42 mm., Rio San Miguel, San Miguel. 
Head 3.1 to 4.3; depth 3.15 to 4.05; D. 8 or 9; A. 9 or 10; scales 28 to 30. 
Body moderately compressed anteriorly; caudal peduncle strongly compressed, 
its depth 1.35 to 2.35 in head; profile nearly straight from snout to nape, slightly 
convex from nape to dorsal; head rather broad, flat above; snout short, broad, 
2.75 to 4.65 in head; eye 2.5 to 4.25; interorbital 2.2 to 3.28; mouth small, the cleft 
transverse; teeth loosely attached, the outer series slightly broadened, curved 
inward, and well separated from the very minute inner teeth; scales cycloid, present 
on head and snout and on base of caudal, each scale with 11 to 20 radii, average of 
30 scales taken from 10 specimens ranging in length from 24 to 63 millimeters, 13.7; 
origin of dorsal in female a little in advance of middle of anal base, equidistant 
from tip of snout and end of caudal, or a little nearer the former; dorsal placed 
further forward in the adult male, about half the length of head, nearer tip of 
snout than end of caudal; caudal fin broad, gently convex; anal fin in females and 
young similar to dorsal, its origin a little nearer base of caudal than posterior 
margin of eye; anal fin in adult males inserted far in advance of dorsal, greatly 
produced, much longer than the head, reaching nearly to base of caudal in sexually 
mature but small males, proportionately shorter in larger specimens, the third, 
fourth, and fifth rays all of about equal length, the branches greatly crowded distally 
and forming a compound curve, the apex being directed forward, two of the branches 
of the median produced ray bearing about 12 spur-like hooks on their posterior 
margins; ventrals reaching vent in small females, proportionately shorter in large 
