174 FISHES OF WESTERN SOUTH AMERICA 
dad were nearer C. venezuelanus von Ihring than to his description of C. aeneus. 
“The specimens from which aeneus was described were 63.5 to 101.6 mm., those 
from which venezuelanus was described were 35-45 mm., which may account for the 
variation in proportion of height to length found by the two authors.” Mrs. 
Ellis’s three specimens were 60-80 mm. 
Gill’s aeneus had the greatest height less than one fifth the total length, 
venezuelanus is described as having the height 2.66 in the length to the base of the 
caudal fin; the interorbital space in the former is less than the snout, in the latter 
greater than the length of the snout. 
My material from the foothills of the Peruvian Andes is as follows: 
D. 1,8; A. I, 7; interorbital 2 or more in the head; depth 3.0-8.3 in the length; 
barbel to or not to gill-opening; eye 2.25—2.5 in the interorbital, 4-5 in the head; 
5-6 azygous plates in front of the adipose; humeral plate and streak from it back- 
ward dark, fading out before reaching caudal;streak along middle of back dark, 
with a lighter line separating it from the previously-named dark areas. 
99-95 
Plates: 9272" 
148. CorypDORAS ARMATUS (Ginther) 
Callichthys armatus Giinther, 1868, Proc. Zool. Soe. London, 230, fig. 1, three, types, 160 mm., 
Xeberos; seven, 55 mm., R. Huallaga. 
Corydoras armatus Cope, 1871, Proc. Acad. Nat. Sei. Phila., X XIII, 282, Rio Huallaga, Xeberos; 
Cope, 1874, Proc. Acad. Nat. Sci. Phila., XX VI, 135, Nauta; 
Eigenmann and Eigenmann, 1888, Proc. Cal. Acad. Sci., (2), I, 166; 
Bigenmann and Kigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 471; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, HI, 403; 
Regan, 1912, Ann. Mag. Nat. Hist., (8), X, 215; 
Gosline, 1940, Stanford Ichth. Bull., Il, 1, 19. 
Gasterodermus armatus Cope, 1878, Proc. Amer. Phil. Soc., XVII, 681, Nauta. 
Peruvian Amazon and tributaries; Rio Jurud 
149. CoRYDORAS ELEGANS Steindachner 
Corydoras elegans Steindachner, 1876, Sitab. KIx. Akad. Wiss. Wien, LX XIV, 93, Cudajas, Teffé; 
Eigenmann and EKigenmann, 1890, Occ. Papers Cal. Acad. Sci., I, 469; 
Regan, 1913, Ann. Mag. Nat. Hist., (8), XII, 281, Rio Ucayali; 
Gosline, 1940, Stanford Ichth. Bull., II, 1, 19. 
Ucayali and Solimoes rivers 
150. CoryDORAS AMBIACUS Cope 
Corydoras ambiacus Cope, 1872 (1871), Proc. Acad. Nat. Sci. Phila., XXIV, 280, Rio Ambyiacu; 
Fowler, 1915, Proc. Acad. Nat. Sci. Phila., LX VII, 232, types of both ambiacus and trilineatus 
Cope; 
Gosline, 1940, Stanford Ichth. Bull., II, 1, 19. 
Corydoras trilineatus Cope, 1871 (1872), Proc. Acad. Nat. Sei. Phila., XXIV, 281, pl. vi, fig. 2, 
Rio Ambyiacu; 
