eigenmann: tetragonopterid characins. 101 



Hyphessobrycon copelandi Durbin, sp. nov.i 



Head 3.5-3.8; depth 3-3.2; D. 11; A. 28 ; scales 5-7+24 to 27-3|; eye 

 2.25-2.33; iaterorbital 2.8-3. Five teeth iu the second row of the premaxillary. 

 First six rays of the dorsal with a submarginal black bar, bordered above and 

 below with chalky white. Anal usually plain. A vertical humeral spot. Margin 

 of caudal dusky. Outer rays of ventrals and pectorals chalky-white. 



A hundred specimens, 29-42 mm. long. Tabatiuga. 



Hyphessobrycon bentosi Dorbin, sp. nov.2 



Distinguished by having eight teeth iu the inner series of the premaxillary. 



Head 3.33-3.5; depth 2f-3i ; D. 11; A. 27-30; scales about 30-33; eye 

 2.5 ; interorbital less than eye. 



First three dorsal rays tipped with white ; a black spot bordered by white on 

 distal half of the second to the sixth ray ; basal part of dorsal hyaline ; a humeral 

 spot, no caudal spot. 



Twenty-one specimens, 30-38 mm. long. Obidos. 



Hyphessobrycon panamensis Durbin, sp. nov. 



Head 3.4; depth 2.8; D. 11; A. 25; scales 7-12+24-6; eye 2.25 in head; 

 snout 4 ; interorbital 3. 



Upper scales margined with dusky ; a dusky lateral band ; first haK of anal 

 tipped with black, other fins plain. 



Seven specimens, 29-32 mm. long. Panama. 



One specimen, 32 mm. Eoqueron River, Panama.^ 



Hyphessobrycon melazonatus Durbin, sp. nov. 



Head 3.5 ; depth 2.66-2.5 ; D. 11 ; A. 22 ; scales 5-34-3.5 ; eye 2.66 in head; 

 interorbital equals eye ; a narrow naked border on the cheek. 



Webs of the dorsal and sometimes those of the first seven or eight anal rays 

 dusky ; caudal peduncle largely dark ; a very faint humeral spot. 



One specimen, 38 mm. long. Lago do Maximo. 



One specimen, 34 mm. Silva, Lake Saraca. 



Moenkhausia latissimus, sp. nov. 



Resembling M. steindachneri in coloration and compressed preventral region and 

 keeled predorsal area. Distinguished by the entire scales, the small nuchal scale 

 and much longer anal, etc. 



1 .In memory of Herbert Copeland of the Thaj'er Expedition. 



2 In memory of Colonel Bentos, a volunteer of the Thayer Expedition. 



* This specimen was submitted for examination by Dr. B. W. Evermann. 



