142 THE CYPRINODONTS. 
From the former it differs in the long anal fin, the deep caudal pedicel, 
and the sharp compression between ventrals and caudal; while it is dis- 
tinguished from the latter by the short dorsal, its posterior position, and 
the depth and compression of the hinder portion of the body. The structure 
of the jaws and mouth remove it entirely from Haplochilus. 
Pterolebias longipinnis sp. n. 
Plate III. Fig. 14, teeth. 
B. 6; D. 10-9; A.20-19; V.8; P. 16-15; Ll. 31-32; Ltr. 10-11; Vert. 
15+ 16. 
Body of moderate length, depth three and two thirds times in the length, 
without the caudal; caudal portion deep, thin, sharp at the lower edge. 
Head depressed, crown flattened, three and one half times in the length to 
the caudal fin. Snout short, half as long as eye, curved from orbit to orbit. 
Eye large, less than three times in head, one and one half times in forehead, 
longer than snout. Mouth wide, extending close to the eye, oblique; sym- 
physes firm; lower jaw prominent, upper short not very protractile. Man- 
dibles comparatively long. Teeth subconical, hooked, in bands, outer series 
larger, in open order. Pharyngeal teeth resembling the maxillary but stouter, 
some usually worn off on the tops like molars. Scales large; lateral line 
distinct. Fins elongate, varying much in shapes among individual specimens, 
bases scaly. Dorsal small, pointed, first ray four fifths of the distance from 
snout to caudal, above fourteenth ray of anal. In cases some of the rays are 
nearly as long as the head and extend upon the caudal. Anal long, deep, 
reaching the caudal, pointed behind, rounded below. Ventrals narrow, 
anterior rays near half as long as body without head or caudal, with the 
filamentary prolongation, reaching hind end of base of anal; bases under 
mid-length of pectorals in males, and under their tips in females. Caudal 
broad, pointed, long, in one case as long as the body without the caudal 
or head. 
Females of one and three-fourths inches with fully developed ova. 
Olivaceous or brownish, darker on chin, back, and edges of fins. All fins 
with small spots in transverse series, fainter on ventrals and anal. Ventral 
surface little lighter. Largest specimen three and two tenths inches in 
length, one and three tenths of this being caudal. Santarem. 
