CHARACINIDAE FROM VENEZUELA—SCHULTZ 237 
It appears necessary to explain my methods of counting and record- 
ing fin rays both for the characins and for the Nematognathi reported 
upon previously. The use of small Roman numerals for the simple 
unbranched soft rays of all fins was not without precedent and was not 
intended to represent the evolution or homologies of true spines or 
soft rays but was adopted as a practical means of indicating the fact 
that the first soft rays are often unbranched, flexible, and nonpungent. 
Furthermore, I find that the separation of the unbranched from the 
branched rays, especially for the pectoral fins, is of prime importance 
in distinguishing genera and species. Many authors have wholly 
neglected to study the pectoral fin rays, thereby missing a valuable 
diagnostic character. In characins, counting only the branched or 
principal rays is not adequate, though most authors agree that it is a 
sufficient count in American Cyprinidae. I did not observe that the 
number of unbranched or branched rays of characins or Nematognathi 
changed with age, as has been noted in certain groups of fishes. 
Simple, unbranched soft rays are represented by small Roman 
numerals and the branched soft rays by Arabic numerals thus: ii, 8. 
Pungent spines are represented by large Roman numerals, although 
no true spines occur in the Characinidae. In the case of the caudal 
fin only branched soft rays were counted, and these are sometimes 
separated in a formula, as 9-+8, which indicates 9 rays in dorsal part 
ef caudal fin and 8 in the lower lobe. 
I counted all rudimentary rays in the dorsal, anal, pectoral, and 
pelvic fins and counted as a single ray each that had a separate base. 
In cases where the last ray was divided at the base, this was counted as 
one ray. However, many of the genera and species reported upon 
here did not have the last ray of either dorsal or anal fins divided at the 
base. 
Other terms will be found self-explanatory as the species involved 
are carefully studied. 
Order HETEROGNATHI 
Family CHARACINIDAE 
The Characinidae belong to the great group of ostariophysan 
fishes having the Weberian apparatus, which consists of the first four 
vertebrae modified into a series of bony ossicles that connect the air 
bladder with the auditory apparatus or ear. 
This diverse family of fresh-water fishes, found in both Africa and 
South America, is most closely related to the Nematognathi, or cat- 
fishes, and to the Cyprinidae. The characinids have evolved so 
many diverse elements and specialized forms in this vast territory 
that the family cannot be defined by any one character; instead, we 
