30 BULLETIN 95, UNITED STATES NATIONAL MUSEUM. 



viduals from the Eimac River, three rows of golden spots, one on 

 each scale, along the rows of scales, and in the smaller indiA'iduals 

 the plumbeous lateral band is distinct. 



Color in life of Pacasmayo specimens, olivaceous, white below; 

 four rows of the large scales are marked with bright orange spots. 

 (These are the third, fourth, fifth, and sixth longitudinal rows, 

 counting from the back.) Pectoral, ventral, and anal tinted with 

 reddish orange ; caudal margined posteriorly with reddish : at middle 

 of base of caudal is a spot of very dark green, almost black. 



In the three specimens taken from a " pozo " between Amotape 

 and Tumbes, the scales are lost, the fins broken and the body appears 

 much shrunken, giving these individuals quite a different appearance. 

 The black caudal spot is quite distinct and the fin counts are the 

 same. 



The " pozo," where these fish occurred in abundance, is a small 

 spring, the outlet of which flows but a short distance before it dries 

 up and disappears. It corresponds closely to the " cenote " of 

 Mexico. 



Family SILURIDAE. 



THE CATFISHES. 



KBY TO GENEEA. 



'. Nostrils close together, neither with a barbel, the posterior with a valve; 

 teeth on the palate; caudal forked. (Species chiefly marine.) Lower jaw 

 with 4 barbels ; palatine teeth fixed ; both jaws with teeth. Gillrakers 



few, 5 to 25 ; eyes above level of mouth 



Galeichthys (p. 30), including Tachy.'iurus, p. 32. 

 '. Nostrils remote from each other. (Freshwater species.) I'osterior nostril 

 without barbel ; barbels, 6 ; adipose fin well developed ; teeth in villiform 

 bands. Teeth on vomer none, or in small patches. Head covered with 

 soft skin above, not granulated. Snout broad, scarcely produced ; barbels 

 terete or slightly flattened, not margined ; head longer than broad. 

 &\ Occipital process, if present, not reaching the dorsal plate; dorsal spine 



pungent Rhamdia, p. 33. 



b". Occipital process narrow, reaching the dorsal plate ; fontanel reaching 

 base of occipital process, a bridge across it above posterior margin of 

 eye; humeral process spine-like Pimelodella, p. 33, 



Genus GALEICHTHYS Cuvier and Valenciennes. 



KEY TO SPECIES. 



'. Head and occiput entirely covered by flesh and skin; occipital process 

 sparingly granulated peruvianus, p. 31. 



'. Occipital process and bones of head exposed or covered with very thin skin ; 

 bones on top of head and occipital process granular ; palatine teeth in 

 large ovate patches simonsi, p. 31, 



