FISHES OF EL SALVADOR 
247 
Metapan, and common in the Rio Sucio at Sitio del Nino and in the Rio Lempa at 
Suchitoto. Elsewhere it was not seen. 
The sexual organs in the fishes examined were in a collapsed condition, showing 
that spawning was not taking place during the period (January and February) 
when the specimens were collected. The air bladder is large and the alimentary 
canal is short. The contents of 4 stomachs examined consisted of fragments of 
insects and the scales of fish, which apparently remained after the rest of the fish 
had been digested. 
The specimens from El Salvador evidently represent a species distinct from those 
of Panama. Material from other Central American countries is not available to 
the author for comparison. Giinther, the discoverer of R. guateinalensis , considered 
his specimens from the Pacific slope of Guatemala identical with others obtained in 
the Rio Chagres in Panama. Authors, generally, had recognized but a single species 
from Central America. Meek and Hildebrand (Pub., Field Mus. Nat. Hist., Zool. 
Ser., X, 1916, pp. 291-3), however, found that the specimens from the Pacific slope 
of Panama were different from those of the Atlantic slope, and they described the 
former as new, giving it the name occidentalis. The Atlantic specimens were con- 
sidered as R. guatemalensis of Giinther, which is probably correct, for Giinther, 
when describing the species, had some young from the Pacific slope of Guatemala 
and adult specimens from the Rio Chagres, Panama. Giinther's description appears 
to have been based upon the adult fish, for he says: " Back elevated, the upper profile 
of the head and nape forming an S-shaped curve." This appears never to be true 
of the young of the genus. The Atlantic representatives from Panama, therefore, 
may for the present, at least, be considered the true guatemalensis, regardless of 
whether or not they are identical with specimens from Guatemala, which seems 
highly doubtful. 
The El Salvador specimens differ from both the Panama species with which a 
direct comparison of specimens has been made, in having a smaller eye, shorter 
fins, in color markings, and in other minor respects. The number of scales in a 
lateral series appears to be nearly identical in the present species and in R. occiden- 
talis. The number of gill rakers, however, is more nearly that of R. guatemalensis. 
In the position of the dorsal and anal the El Salvador specimens appear to be 
intermediate. 
The diameter of the eye in the body in 12 specimens of the present species 
varying from 60 to 82 millimeters in standard length, ranges from 11.8 to 13.5, 
the average bemg 13.35. In an identical series of guatemalensis the range is from 
9.4 to 13.1, average 11.63; in occidentalis the range is 10.03 to 13.3 and the average 
11.64. The length of the fins in the body for 20 specimens from El Salvador, rang- 
ing in standard length from 28 to 86 millimeters, are as follows: Pectoral, 4.5 to 
5.8, average 5.32; ventral 5.1 to 6.43, average 5.81; dorsal 3.44 to 4.3, average 3.94. 
The results for a similar series of R. guatemalensis are as follows: Pectoral 4.55 to 
5.55, average 4.92; ventral 4.6 to 5.8, average 5.21; dorsal 3.2 to 3.66, average 
3.51. For occidentalis, also using a like series of specimens, the followuig results 
were obtained: Pectoral 4.2 to 4.94, average 4.63; ventral 4.03 to 5.05, average 
4.68; dorsal 3.1 to 3.5, average 3.32, The Salvador specimens, therefore, represent 
