136 THE CYPRINODONTS. 
lighter, as also lower surface of head. Centres of scales darker. Dorsal and 
caudal with transverse series of small spots, often irregular, sometimes absent. 
An ocellate spot on the bases of the caudal rays in the upper half of the fin 
is not always present. Pectoral and anal somewhat clouded in large speci- 
mens. Top of head between the eyes darker. Longest example one and 
three eighths inches. 
Para; Gurupa. 
Rivulus micropus. 
Plate III. Fig. 13, teeth. 
Fundulus micropus Steind., 1863, Sb. Ak. Wien, XLVIII, 184. 
Rivulus micropus Gthr., 1866, Cat., VI, 327; Cope, 1878, P. Am. Phil. Soc., XVII, 695; Jor., 1887, 
P. U. S. Mus., IX, 564; Hig., 1891, P. U.S. Mus., XIV, 64. 
Rivulus (Fundulus) micropus Steind., 1880, Denk. Ak. Wien, XLII, 86. 
Haplochilus Hartii Blgr., 1890, Ann. Mag. Nat. Hist., (6) VI, 190. 
B.6; D. 8-9; A. 14-15; V.6; P. 13-15; Ll. 42-44; Ltr. 11; Vert. 
14+ 18. 
Form rather elongate, compressed backward, depressed from the shoul- 
ders forward, depth about two ninths of the length to the caudal. Head 
broad, flattened on the crown, five and a half times in the length with the 
caudal or four and a half without it. Snout broad, rounded, hardly as long 
as the eye. Eye large, three and a half times in the head, twice in the fore- 
head. Mouth medium, nearly horizontal; upper jaw shorter ; symphyses 
firm. Teeth simple, pointed, hooked, outer series larger, not in contact ; 
inner in bands. Dorsal small, origin above hind part of anal, three fourths 
of the distance from the snout to the base of the caudal. Anal larger, base 
extending farther forward than that of dorsal and nearly as far backward. 
Caudal broad, fan-shaped, regularly rounded, as long as head. Ventrals 
small. Pectorals not large, with rounded margins. 
Olivaceous, darker on back and top of head, lighter to whitish beneath. 
Centres of scales on flanks darker. Fins lighter with darker edges. Lower 
lip darker. Dorsal fin with vermiculations or irregular series of small spots, 
or uniform. Caudal in many cases with white edge above and below, occa- 
sionally a black blotch in the white. Specimens of less than two inches are 
lighter colored and have a light band more or less marked by blotches along 
the back, while the dark in the middle of each scale on the flank forms vitte ; 
a dark spot surrounded by white on the upper portion of the base of the tail 
is not rare. As the individual grows darker the spot is undistinguishable. 
Largest example three and one eighth inches. 
Trinidad ; Rio Negro. 
