130 THE AMERICAN CHARACIDAE. 
reaching to above anal; alimentary canal about equal to the entire length of 
the fish; seven pyloric coeca. Intestine contains debris of minute insects and 
plant fibers. 
Vertebrae 13 + 15. 
8. Pristetua Eigenmann. 
mpiorns = a saw, i.e.the fully dentate maxillary. 
Pristella EIGENMANN, Bull. M. C. Z., 1908, 52, p. 99. 
Typr.— Holopristes riddlei Meek. 
This genus differs from Hemigrammus much as Hemibrycon differs from 
Astyanax. 
Lateral line incomplete, caudal scaled for at least one third of its length; 
maxillary with teeth along nearly the entire anterior edge; gill-rakers long, 
setiform; gill-membranes free from each other and from the isthmus. 
Hapirat.— Coasts of Guiana and Orinoco. 
Key to the Species. 
a, Depth 2.3-2.75; A. 20-24; dorsal, anal, and very frequently ventral, each with a conspicuous black 
Spots) MO; CAUGKL POL, Le ae « o.25- ical eaeisy tn shared Be one etetele aks oe eeteaiea tiers if 
riddlei (Meek). 
aa. Depth 3.5; A. 16-18; caudal with a spot on the base of its middle rays, other fins all plain. 
2. aubynei Eigenmann. 
1. PRISTELLA RIDDLEI (Meek). 
Plate 13, fig. 2. 
Holopristes riddlei Murx, Proc. U. 8. N. M., 1907, 33, p. 11 (Los Castillas). 
Pristella riddlei E1GENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 437; Mem. Carnegie, 
mus., 1912, 5, p. 330, pl. 45, fig. 3. 
Hapirar.— Guiana and Venezuela. 
Specimens examined. 
Number of Size 
Catalogue number specimens in mm. Locality 
10896 Type 1 about 29 Los Castillas 
— Paratypes ! 4 29-31 Los Castillas 
1317 C. 11798 I. 56 12-29 Wismar, Demerara River 
1308 C. 11800 I. 8 37-47 Georgetown Trenches 
1309 C. 11796 I. 233 26-45 Botanic Garden, Georgetown 
1310 C. 11799 I. 5 Christiansburg Canal 
1311 C. 11797 I. 3 Kumaka 
' Collection of Field Museum, Chicago. 
Collector 
Riddle 
Riddle 
Eigenmann 
Eigenmann 
Shideler 
Eigenmann 
Eigenamnn 
