394 FISHES OF WESTERN SOUTH AMERICA 
Acara syspilus Cope, 1871, Proc. Acad. Nat. Sci. Phila., XXIII, 255, pl. xi, fig. 3, Rio Ambyiacu; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 690; 
Boulenger, 1887, Proc. Zool. Soc. London, 275, Canelos. 
Aiquidens syspilus Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 138; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 472. 
Peruvian and Ecuadorean Amazon 
Haseman examined the types of Cope, and unhesitatingly places his Acara 
syspilus under 4. vittatus of Heckel. 
506. ASQUIDENS SUBOCULARIS (Cope) 
Acara subocularis Cope, 1878, Proc. Amer. Phil. Soc., XVII, 696. 
Aquidens subocularis Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 472; 
Haseman, 1911e, Ann. Carnegie Mus., VIT, 388. 
Geophagus thayeri Pellegrin, 1903 (1904), Mém. Soc. Zool. France, XVI, 189. 
Peruvian Amazons 
507. ANQUIDENS HERCULES Allen, sp. nov. 
Plate XXII, figs. 4-7 
17736, 13, 38-132 mm., the largest the type, creek, Rio Morona, Allen, October, 1920. 
These thirteen specimens from near the Peruvian-Ecuadorean frontier and 
taken within only a few miles of the foothills of the Andes, exhibit many resem- 
blances to known species of quidens, but fail to conform to the descriptions of 
any of them, and are unlike any specimens available for comparison. 
Head 3.15-3.3; depth 2.4-2.7; D. XVI-XVII, 8; A. III, 6-7; lateral line 18 + 8 
to 11; scales 27-29 along a middle line from the end of the opercular opening; eye 
2.8-3.4 in the head, exceeds the preorbital space, and interorbital in the young; 
eye in the middle of the head except in the smallest, in which it is in front of the 
middle; dorsal profile more arched than the ventral, especially with age, depressed, 
or at least flattened, between the eyes, in a plane tangent to the orbit in younger 
specimens, and more depressed with age. 
The fish is elongated in shape; the caudal peduncle a fifth longer than deep. 
Mouth small, maxillary not reaching eye; maxillary-premaxillary border 2.6— 
2.8 in the head; lower gill-arch with 8—9 small, papillose gill-rakers; cheeks with 
three rows of scales, preopercle naked; one and one-half to two and one-half scales 
above the lateral line; fins naked except the caudal, which is scaled at the base; 
lateral line has only an indication of forking on the caudal fin in the younger 
specimens. 
Dorsal spines are subequal from the fourth, and about half the length of the 
head; pectorals and ventrals longer than the head; caudal fin rounded at the end. 
A series of six sub-rhomboidal dark areas along the middle of the body to the 
base of the caudal; four or five additional blotches of more shadowy character from 
the base of the dorsal fin to the lateral line scales, alternating with the above; verti- 
