THE CYPRINODONTS. 139 
chen besetzt, zuweilen auch die Caudale. Die iibrigen Flossen stets unge- 
fleckt ; Caudale am hinteren Rande zuweilen (bei Miinnchen) breit, weisslich 
gesiiumt und in der vorderen Hiilfte stets dicht iiberschuppt. 35-36 Schup- 
pen zwischen dem oberen Ende der Kiemenspalte und dem Beginne der 
Caudale in einer Liingsreihe und 114 zwischen der Mittellinie des Riickens 
und der Basis des iiusseren Ventralstrahles in einer Querreihe. 
Cauca. (Steind.) 
Closely allied to 2. micropus, of which it may yet prove to be a variety. 
Rivulus ornatus sp. n. 
B. 6-5; D.6; A. 10-11; V.6; P. 12-14; Ll. 31; Ltr. 8. 
Shaped like the majority of the species in the genus. Head one fourth 
of the length to the base of the caudal, broad, flattened on the crown, de- 
pressed. Snout broad, rounded, about as long as the eye. Eye one fourth 
of the head, one half of the interorbital space. First ray of dorsal above 
last of anal, two thirds of the distance from the base of the pectoral to the 
base of the caudal, or three fourths of that from the front edge of the eye 
to the caudal. First ray of anal half way from head to base of caudal. Ven. 
trals small, not reaching the anal. Pectorals elongate, as long as the head, 
reaching nearly to the ventrals. Caudal elongate, pointed. 
The markings of this fish are made up of puncticulations ; they form 
transverse blotches along the back, streaks along the sides, series of dots 
across the fins, a dark band on the lower lip, and a dark streak backward 
from below each eye. In cases light bands on the back meet dark vertical 
bars on the flank. Some specimens are dark brownish, others very light. A 
few are quite dark on the back. The longest measure one and three eighths 
inches. 
Silva; Cudajas; Lago Alexo; Lake Hyanuary. 
The formula D.6; A. 8; P. 12; Ll. 26; Ltr. 6, is taken from an indi- 
vidual resembling the preceding in position of dorsal and anal, but lacking 
the blotches and bearing a streak from occiput to caudal and another from 
anal to caudal. Other collections may prove this to belong to a distinct 
species. It was obtained in Lago Alexo. 
