236 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
this report. Specimens already in the collections of the United States. 
National Museum were also used, and a few cthers were borrowed 
for study from the California Academy of Sciences, the American 
Museum of Natural History, the Chicago Natural History Museum, 
the Natural History Museum of Stanford University, and on 
Dr. William Beebe, New York Zoological Society. 
There are recorded herein from Venezuela 58 genera and 117 species 
and subspecies of the Characinidae. These numbers should be 
considerably increased when adequate and further collecting of 
fishes is done in the Orinoco River system and in the coastal drainages 
of Venezuela. Three genera (one from the Orinoco system) and 17 — 
species and subspecies (12 from the Maracaibo Basin and 5 from the 
Orineco drainage) are here described as new to science. I was able 
to collect only in certain restricted regions of the Maracaibo Basin, 
and there is little doubt that many more new forms will be revealed 
when further collections are made in that basin. 
At present, 29 species of characins are known from the Maracaibo 
Basin, and only two of these are found in the Orinoco system. One, 
Hoplias malabaricus, appears to be the same form along the coast 
from the Magdalena system to Brazil; but the other, a Creagrutus, 
may prove to be a distinct subspecies when the series from the Orinoco 
system are carefully compared with those from the Maracaibo Basin. 
Several species show close relationships with similar ones in the 
Magdalena River system. The only species reported from the 
Maracaibo Basin but not obtained by me is Piabucina erythrinoides, 
and this comes from a locality I did not visit. 
Except in a few instances, subfamilies of the Characinidae as used 
by authors are omitted from the present treatment because they are 
not well defined. 
No attempt will be made to discuss the distribution of the fresh- 
water fishes of Venezuela until the other groups represented in the 
collections have been studied. 
DEFINITION OF TERMS 
Terms used in this report are defined as follows: 
Standard length is measured from tip of snout to midbase of caudal 
fin; length of head is the distance from tip of snout to rear end of fleshy 
operculum; depth is greatest depth of body; snout is from tip of snout 
to front of eye; distance between nostrils or nostrils to eye is measured 
from edge of nasal openings; interorbital space is fleshy distance be- 
tween eyes; postorbital length of head is distance from eye to rear end 
of fleshy operculum; caudal peduncle length is measured from base of 
last anal ray tomidbase of caudal fin; distances involving the anus are 
measured from center of anus. 
