ANNOTATED LIST OF THE SPECIES 287 
externally, and forming a straight line closely fitting the straight, untoothed edge 
of the mandible; each maxillary tooth with about 10-11 minute, dark-colored, digit- 
like denticles, forming the cutting edge; maxillary teeth about two each side, curved 
too far medially to be in line with the premanxillary teeth, smaller, with fewer 
denticles. Mandible with anterior margin narrow, straight, its ramus constricted 
midway, spatulate, edentulous, weak; gill-rakers fine, close-set, curved, short, 19 
on lower arch. 
Origin of dorsal fin equidistant from end of snout and distal end of adipose fin, 
or nearer to snout; dorsal fin short and low, its height 5.4 in the standard length; 
adipose feebly developed; caudal fin moderate, 5.3 in the length; anal low, broad, 
sub-triangular, 7 in the length; ventrals directly beneath the dorsal, tips not quite 
reaching the vertical from the tip of dorsal; pectorals broad, tips separated from 
the origin of the ventrals by four scale-rows; paired fins low and horizontal as in 
benthic types generally. 
Lateral line straight; scales with three or more radials; edges turned sharply 
outward, outlining each scale with a pronounced epidermal eminence; axillary scales 
well developed; fins naked except caudal, whose lobes have 4-5 rows each of scales, 
diminishing in number and increasing in size to a single large scale (or two) midway 
on the lobes. 
A dark band originates on the snout, encloses the nares and the eye, becomes 
fainter on the opercle, continues darkly along the lateral line 14 scale-rows in width, 
to the end of the middle caudal rays, expanding in older specimens to the proximal 
half of the first half-dozen rays of the lower lobe; diffuses in the lower lobe to numer- 
ous, minute, irregular chromatophores. A second band arises above the eye and 
passes about one scale’s width at a scale’s distance below the dorsal fin, uniting 
with the corresponding band of the opposite side at the adipose, along the median 
seales to the caudal fin, there diffusing downward a little way into the dorsal lobe. 
A third band runs medially from the occiput to embrace the dorsal basis. A faint 
patch on the base of the lowest caudal rays; areas between the bands a dull, brassy 
yellow (alcohol), without markings on the lower sides, but upward from the lateral 
line sprinkled with scattered chromatophores, finely dotted along the radials of the 
scales. 
The name is in reference to the only known locality, a small woodland stream 
opposite Puerto Melendez, just below the Pongo de Manseriche, where the Peruvian 
Amazon bursts through its last mountain barrier into the lowlands, at about 1500 
feet elevation. (Pronounced mahn-say-reé-chay.) 
Subfamily: NANNOSTOMATINAE 
Minute fishes having broad teeth with equal points and equal jaws; skull 
truncate; occipital process wanting; no fontanel, lateral line, or adipose fin. 
Genus 155: POECILOBRYCON Eigenmann 
Poecilobrycon Eigenmann, 1909, Ann. Carnegie Mus., VI, 43; 
Jigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 427; 
Rigenmann, 1912, Mem. Carnegie Mus., V, 283. 
