BULLETIN OK THE UNITED STATES FISH COMMISSION. 35 



Maxillary barbels compressed and band-shaped, their attenuated tips 

 reaching more or less past the front of the anal fin. Mental barbels 

 short, nearly 3 in head. 



Occipital process longer than broad, ascending- rather steeply back- 

 ward, forming an angle with the rest of head, reaching nearly to the 

 base of the dorsal, its surface covered with smooth skin. Foutanelle 

 rather broad, extending from the snout to the base of the occipital 

 process, its posterior part narrow, groove-like. Shields of head mostly 

 smooth, the temporal region and occipital process often with small gran- 

 ulations. Cheeks hard and prominent, the region between them and top 

 of head somewhat concave. 



Dorsal spine ending in a long, band-like, obliquely striated and ar- 

 ticulated filament, which extends more or less past base of caudal. 

 Adipose fin short and high. Caudal widely forked, the upper lobe 

 somewhat longest, about one-fifth longer than head. Anal somewhat 

 emarginate, a little shorter than head, the anterior lobe falling con- 

 siderably short of the base of the fin. Pectoral spine ending in a band- 

 like filament like that of the dorsal spine; the filament varying in length, 

 usually reaching nearly to last rays of anal. Humeral process covered 

 by soft skin. 



Color dark brown, with bluish luster, silvery below; around pale spot 

 in the center of fontanelle (traces of which are seen in all our species 

 of Arius and ^Elurichthys) ; fins all pale; the anal with a large, roundish, 

 black blotch in front; the upper edge of the ventrals usually, but not 

 always, with a similar black blotch. 



This species is generally abundant along the Pacific coast of tropical 

 America, although less common than JElurichtliys panamensis. It 

 reaches a length of about 2 feet. Specimens were obtained at Mazat- 

 lan and Panama. 



SPECIMENS IN UNITED STATES NATIONAL MUSEUM. 



2. JGlurichthys panamensis Gill. — Bagre. 



JElurichthys panamensis Gill, Proc. Ac. Nat. Sci. Phila. 1863, 172 (young; Pan- 

 ama); Giinther, Fishes Centr. Amer. 1869, 476 (copied from Gill); Stein- 

 daclmer, Ichth. Beitriige, iv, 14, 1875, taf. ii (Magdalena Bay; Altata ; 

 Panama). 



JElurickthys nuchalis Giinther, Cat. Fishes Brit. Mus. v, 179, 1865 ( $ , Panama); 

 Giinther, Fishes Centr. Amer. 476, 1869, pi. 81, f. 2. 



Habitat, — Pacific coast of Central America; Magdalena Bay; Maz- 

 atlan; Altata; Punta Arenas; Libertad; Panama. 



Head 3f (4f) ; width of head 4£ ; depth 4£. D. I, 7 ; A. 5, 21. Length 

 (29174) 18 inches. 



