ANNOTATED LIST OF THE SPECIES 389 
497. ACARONIA TRIMACULATA Allen, sp. nov. 
Plate XXII, fig. 8 
17794, 5, 110-162 mm., the largest the type, Iquitos, Morris, 1922. 
An Acaronia of very different form from the genotype, massa, appears in the 
material assembled by Morris at Iquitos. 
Head 2.6-2.8; depth 2.0-2.3; D. XIV or XV, 9-10; A. III, 7; scales 23-25 along 
the middle line, lateral line scales separated by a scale and a half from the soft 
dorsal fin; lateral line 17—18 + 9—9; eye 3.3-3.6 in the head, 1.3-1.7 in the inter- 
orbital space. 
Snout as in quidens; mouth slightly oblique, jaws equal; mouth only moder- 
ately large, but maxillary not reaching the eye; several rows of conical teeth; rakers 
of first gill-arch few, large, and fungiform; on remaining arches 9-10, stout, not 
closely set. 
Dorsal and anal fins naked, but base of caudal fin scaled; pectorals mostly 
hyaline, reaching to the origin of the anal fin; ventrals inserted slightly behind the 
origin of the dorsal fin; soft dorsal and anal fins drawn out to a filament reaching 
the middle of the caudal, black-tipped; ventrals also tipped with black, and with 
a filament reaching the caudal peduncle; fins elsewhere mottled, almost taking 
shape as oblique bands on the caudal; dorsal spines graduated, the last the longest, 
equal to the snout before the orbit, caudal peduncle about as long as deep. 
Eye at the middle of the head, three rows of scales on the cheek. Approaching 
the venter the body scales become bordered with silver. 
Three distinct black spots as follows: (1) a double one bordering the cheek on 
its caudal margin, contrasted sharply with silvery preopercle, and broadening at 
the level of the eye so as nearly to reach the orbit; (2) a spot four scales long by two 
broad, just beneath the lateral line scales, at the level of the tenth to twelfth spines 
of the dorsal fin; (3) the usual ocellus bordered with yellow at the base of the upper 
caudal rays. 
Most clearly separated from A. nassa, the genotype, by the following char- 
acters: more elongated dimensions generally (spines, lateral line, etc.) ; stouter head, 
maxillary not reaching the eye, snout not pointed; number and form of the gill- 
rakers; longer peduncle; no ocellated spot on the head; only a suggestion of a com- 
plete longitudinal band; lateral line more widely separated from the dorsal line. 
Genus 202: UARU Heckel 
Uaru Heckel, 1840, Ann. Wiener Mus., II, 330; 
Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 212, 249; 
Kigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, ITT, 469. 
Type: Uaru amphiacanthoides Heckel 
Brazilian and Peruvian Amazon 
Body of very short, vertical form; teeth of the form of talons or claws, the 
anterior and outside series the larger, compressed, with rounded cusps; maxillary 
