156 THE CYPRINODONTS. 
but somewhat rough with concentric striz, flat, thin, not thickened on 
anterior parts of body or on head; belly entirely covered. Cheek scales, 
below the eye, in three rows, two of which extend forward farther than 
the orbit. Origin of dorsal midway from head to caudal, nearly opposite 
that of anal. Caudal broad, subtruncate, two thirds as long as head. Intes- 
tine about equal to the total length. 
Brown to yellowish brown, clouded or mottled with darker; sometimes 
with three rather indefinite and irregular longitudinal series of blotches on 
the sides. Males and females are adult at a length of two and a half 
inches. 
The species is most closely allied to O. albus and O. luteus, with which it is 
found in Lake Titicaca; from the former it differs in length of snout and 
shapes of head and body, from the latter especially in shape of head, and 
from both in the squamation of the ventral surface. On one specimen of 
eight the rays of which were counted, dorsal and anal have each but four- 
teen rays, indicating a considerable amount of individual variation. 
HAPLOCHILICHTHYS. 
Aplocheilichthys Blkr., 1862, Poiss. Guin., 116, — 1863, Atl., ITI, Cypr., 140. 
Epiplatys Gill, 1863, P. Phil. Ac. (1862) 186, part. 
Lycocyprinus Pet., 1868, Mb. Brl. Ak., 396. 
Corpus elongatum compressum, squamis magnis deciduis vestitum, dorso 
humili, ventre convexo. Caput et rostrum latum depressa. Maxilla superior 
protractilis. Rictus terminalis. Dentes intermaxillares et inframaxillares 
uniseriati, simplices ; vomerini nulli. Os supramaxillare post os inter- 
maxillare rejectum. Pinna dorsalis pauciradiata analis parti posteriori 
opposita in initio dimidii corporis posterioris inserta. Pinne ventrales © 
longe post basin pectoralium insertee Pinna analis media corporis lon- 
gitudine inserta, pluriradiata, altior quam longa. Apertura branchialis 
ampla. Membrana branchiostega radiis 5. (Bleeker.) 
This is Lycocyprinus of Peters, which that author says, in comparing 
with his Nothobranchius, “ebenfalls freie Nebenkiemen, aber gebogene 
Zwischenkiefer und eine kurze, ganz hinten iiber dem Ende der mittellan- 
gen Analflosse stehende Riickenflosse hat. Er hat ebenfalls die Kiemen- 
deckelstiicke deutlich beschuppt und die Zihne der hinteren, so: wie der 
vorderen Reihe etwas grisser.” 
