248 
BULLETIN OF THE BUEEAU OP FISHERIES 
what Dr. C. H. Eigenmann, in several of his recent works, has called a " statistical 
species." 
In color the El Salvador specimens differ from R. guatemalensis in having no 
black in the lateral band, and in having a more or less distinct dark spot on the 
sides, which, however, is much smaller than the one in occidentalis. 
Fowler (Proc, Ac. Nat.Sci., Phila., LXXV, 1923 (1924), p. 25) recently described 
Rcehoides houchellei from Great Falls, Pis Pis River, of the Atlantic slope of Nicara- 
gua. According to the description, this species would appear to be close to the 
present one. It appears to differ as follows, however: (1) In the shorter maxillary, 
which is described as reaching only to the eye, while in the Salvador fish it reaches 
well beyond this point. (2) The preorbital, in comparison with the maxillary, 
is broader, being described as equal in width to the maxillary. In the specimens at 
hand it is always notably narrower. (3) Fowler counts 52 rays in the anal fin of 
his type. The largest number found in 25 specimens from El Salvador is 50. It is 
possible, therefore, that at least the average number for Nicaraguan specimens is 
higher. (4) The pectorals in R. houchellei are described as reaching the anal and 
to be contained 1.66 in head. In the specimens at hand they do not reach the origin 
of the anal, yet they are contained only 1.3 to 1.45 in head. (5) The dark spot on 
the side situated just above the lateral line is described for R. houchellei as being 
"midway in the predorsal length." In the El Salvador specimens it is only about 
an eye's diameter in advance of origin of dorsal. (6) The bright silvery lateral 
band, very evident in all alcoholic specimens from El Salvador, is not mentioned for 
R. houchellei. 
The specimens from El Salvador were collected in lakes Guija, Metapan, and 
in the Rio Sucio at Sitio del Nino, and in the Rio Lempa at Suchitoto. 
Order NEMATOGNATHI 
Family II. ARIID^E 
The Sea Catfishes 
Body elongate; head broad, depressed; nostrils close together, neither with a 
barbel, the posterior with a valve; palatine teeth present; skin naked; dorsal fin 
present, short, situated above or in front of ventrals; adipose fin present; caudal 
fin lunate or forked. 
KEY TO THE GENERA 
a. Teeth all pointed; present on the jaws, vomer, and palatines Galeichthys, p. 248. 
aa. Teeth wanting on the vomer; those on the palatines broad and blunt Arius, p. 250. 
3. Genus GALEICHTHYS Cuvier and Valenciennes 
Oaleichthys Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, 28, (type Galeichthys feliceps Cuvier and Valenciennes). 
This genus may be recognized by the presence of pointed teeth on the jaws, 
vomer, and palatines. The palatine teeth are in small or moderate patches and 
do not have a backward extension. A single species belonging to this saltwater 
genus is present in most fresh waters of El Salvador. 
