1877.] 45 (Cope. 
Color silvery, with a narrow dorsal dusky line, and a leaden shade along 
the upper part of the side, which continues to the notch of the caudal fin. 
The anterior part of this band is enlarged into a scapular spot. 
Nos. 69-70 and 122 from the upper waters of the Urubamba, one of the 
sources of the Ucayale. The other species of this section of the genus, the 
T. polyodon Gthr. is from the neighborhood of Guayaquil. 
Dedicated to the memory of the inca Ypanqui, who in the city of Cuzco 
on the Urubamba, the first of his line, devoted himself to monotheism. 
36. ENGRAULIS TAPIRULUS, Sp. NOV. 
There are minute teeth in both the jaws, and the obliquely truncated 
extremity of the maxillary bone does not reach the articulation of the man- 
dible with the quadrate. None of the fin rays are elongate, and the 
muzzle projects in a compressed, conical form beyond the mouth. The 
length of the head exceeds the depth of the body, and enters the total 
length without the caudal fin, three and one-third times. The depth of the 
body enters the same, four and one-fifth times. The eye is large, the 
diameter entering the length of the head four and one-half times, and ex- 
ceeding the length of the rather elongate gill-rakers. Fin radii; D. I. 11; 
A. 25; the former originating above a point behind the base of the ventral 
fins ; its last rays standing above the base of the first anal ray. Its first 
ray is equidistant between the base of the caudal fin, and the line of the 
anterior border of the orbit. Scales in 36-7 transverse series, deciduous. 
Abdomen moderately trenchant. 
M. 
BUC RIE PETIPOD Eg os ciecd cio sie iste Ala! ajo son cel tala aba a etmle wate w ele o wes 120 
BEIGE Oy OLUL torera oyeyets iene ols lofatela siete elaine vie einie oietele erehersel- .006 
a CP MOLCeI OL OPCRGULUM se escraiere cicieisicrccie cle le are . .080 
“9 CoS VeMt Call fis 2/616 Bratetsiierctaterenecociienorete sdaooeoe .050 
Ge “* anal SA re vavterc Sie Wik aN otaad arstenclais Git, Saeco nck 070 
i so CAC Meh Nersie (a. afafercnsie s fo¥ehs’ ale afore eietsteusitge pacou oily) 
This species is, according to the descriptions given by Dr. Ginther, 
most nearly allied to the H. surinamensis, and H. poeyt, but differs in 
many respects. The two specimens probably came from Pacasmayo Bay. 
37. TRICHOMYCTERUS PARDUS Cope, Proceedings Academy, Phila. 1874, 
p. 182. 
Numerous specimens from Jequetepeque. 
After comparison of this first with many individuals both old and young, of 
the T. dispar, my opinion in favor of its specific distinctness from that species 
is confirmed. In order to present its characters in connection with those 
of other Trichomycteri, the following table is presented. A large specimen 
of the 7. pardus, which, according to the label, came from Callao Bay, 
differs from those from Jequetepeque in having small spots instead of the 
large blotches characteristic of the species : 
I. Dorsal fin entirely in front of anal. 
a. Dorsal partly over base of ventrals. 
