THE AMERICAN TETRAGONOPTERINAE. 109 
29. MoENKHAUSIA COTINHO Eigenmann. 
Plate 9, fig. 1; Plate 101, fig. 2. 
Moenkhausia cotinho E1cENMANN, Bull. M. C. Z., 1908, 52, p. 104 (Para); Rept. Princeton univ. exped. 
Patagonia, 1910, 3, 434; Mem. Carnegie mus., 1912, 5, p. 327. 
Hasirat.— Amazon Basin; Guiana. 
Specimens examined. 
Catalogue Number of 
number specimens Size in mm. Locality Collector 
21013 Cotypes 2 46-54 ? Justa 
(to base of 
caudal) 
21070 Cotypes 3 67-71 Para Thayer Ex- 
pedition 
3729 C. 3 53-55 Villa Bella Haseman 
3730 C. 2 52-55 Manaos Haseman 
By Ge 1 52 Maciél, Rio Guaporé Haseman 
3728 C. 1 54 San Joaquin Haseman 
3747 C. 1 48 Santarem Haseman 
ISIPAGe wakes 35 34-55 Wismar, Demerara River Eigenmann 
1313 C. 11814 I. 33 42-60 Malali, Demerara River Shideler 
1314 C. 11818 I. 22 52-62 Tukeit, Potaro River Eigenmann 
1315 C. 1 64 Cangaruma, Potaro River Eigenmann 
1316 C. 11815 I. 6 45-51 Mud flats below Wismar Eigenmann 
1317 C. 11812 I. 27 44-66 Tumatumari, Potaro River Eigenmann 
1318 C. 11819 I. 17 43-59 Crab Falls, Essequibo River Eigenmann 
1319 C. 11816 I. 7 41-57 Christianburg Canal Eigenmann 
1320 C. 11817 I. 2 35-57 Rockstone, Essequibo River Eigenmann 
Distinguished by its slender form combined with the broad basal caudal bar. 
Head 3.7-4; depth 2.8-3.3; D. 11; A. 19-21. Scales 5-31 to 33-3.5. Eye 
2.71-8. Interorbital slightly greater or less than eye. 
Elongate, not strongly compressed or elevate; dorsal and ventral profiles 
equally curved, without notable depressions or elevations. Preventral area 
rounded or flat, with a median series of scales, bordered by scales not at all or 
but little angulated; postventral area compressed, with a median series of large, 
angulated scales; predorsal area rounded with a median series of nine scales from 
the dorsal to the occipital process. 
Occipital process short, reaching one sixth the distance to dorsal, bordered 
by two or three scales on each side. Interorbital slightly convex; second sub- 
orbital greatly arched, leaving a very narrow naked area; maxillary two and 
