106 THE AMERICAN CHARACIDAE. 
27. MoENKHAUSIA COPEI (Steindachner). 
Plate 9, fig. 3; Plate 101, fig. 4. 
Tetragonopterus copei STEINDACHNER, Flussf. Siidam., 1882, 4, p. 135, pl. 6, fig. 6, (Santarem); E1rcEen- 
MANN & EIGENMANN, Proc. U. 8. N. M., 1891, 14, p. 53. 
Moenkhausia copei E1GENMANN, Rept. Princeton univ. Exped. Patagonia, 1910, 8, p. 438; Mem. Carnegie 
mus., 1912, 5, p. 329. 
Hasirat.— Santarem to Para and British Guiana. 
Specimens examined. 
Catalogue Number of 
number specimens Size in mm. Locality Collector 
20783 30 3444 Santarem Bourget 
21072 1 30 (to Para Thayer Ex- 
base of caudal) pedition 
1321 C. 11824 I. 26 30-56 Wismar, Demerara River Eigenmann 
1322 C. 11821 I. 11 33-56 Gluck Island at Rockstone Eigenmann 
1323 C. 11820 I. 53 27-55 Rockstone, Essequibo River Eigenmann 
1324 C. 11823 I. 42 35-45 Tusaca Pan, Rupununi Grant 
3742 C. 5 40-56 Maciél, Rio Guaporé Haseman 
Closely allied to M. collettii; distinguished by the shorter anal. 
Head 3.66-4; depth 3.33-3.66; D. 11; A. 18-201; scales 5-32 to 34-3.5 
(usually 33 pores in the lateral line). Eye 2.5-2.75 in the head; interorbital 
3 or a little more. 
Slender, little elevated; dorsal and ventral profiles about equally curved, 
nowhere notably depressed or elevated; preventral area flattish; postventral 
area compressed; predorsal area obscurely keeled just in front of the dorsal, 
with a median series of nine scales reaching to the occipital process. 
Occipital process short, less than one fifth the distance from its base to 
the dorsal, bordered by two or three scales on the side; interorbital convex in 
the center, with lateral grooves; frontal frontanel much narrower and about 
three fourths as long as the posterior; second suborbital leaving a naked border 
on the cheek which is widest below; maxillary equals distance from tip of snout 
to pupil; frequently four teeth in the outer row of the premaxillary, of which 
the middle two are close together and remote from the others; five teeth in the 
second row; one or two maxillary teeth; four large teeth in the front of the man- 
dible. 
1 Out of fourteen four have eighteen anal rays, nine nineteen and one twenty. 
