128 Bulletin 4.7, United States National Museum. 



185. NETUMA ELATTURA, (Jordan & Gilbert). 



Head 3|. A. 18. Mouth rather large; vomerine teeth rather coarse; 

 palatine patches small; barbels rather short; occipital process short, 

 broadly triangular, with concave sides, the base abruptly broadened: 

 median keel well developed; fontanelle broad and shallow, with a narrow 

 groove behind, nearly reaching occipital process; shields roughish, but 

 smoother than in N. kessleri; barbels rather short; caudal short, 1| in 

 head. Panama; scarce, (e/ldrrw^, reduced; ovpd, tail.) 



Arius elatturus, JORDAN & GILBERT, I. c., 45, 1882, Panama. 



73. HEXANEMATICHTHYS, Bleeker. 



186. HEXANEMATICHTHYS FELIS, (Linnajus). 

 (SEA CATFISH.) 



Head 31 ; depth 5. D. I, 7 ; P. I, 6; A. 16. Body rather elongate, not 

 compressed, tapering into the slender tail; head subconic, depressed, 

 flattish above ; maxillary barbel nearly as long as the head ; gill mem- 

 branes broadly united, forming a narrow, free fold across the isthmus; 

 occipital process with a median keel, long, about i head, its tip convex ; 

 fontanelle forming a narrow groove ; top of head comparatively smooth ; 

 humeral process nearly i the length of the pectoral spine ; caudal deeply 

 forked, the upper lobe the longer. Steel blue, sides and belly silvery, 

 lower fins pale. L. 24 inches. Cape Cod to Texas; common southward 

 along the sandy coast, the most abundant of the salt-water catfishes on 

 the United States coast, and the only one of the Tachysurus type found 

 much north of the Tropic of Cancer, (fells, cat.) 



Silurusfelis, LINN;EUS, Syst. Nat., Ed. xn, 503, 1766, Charleston, S. C. 



Arius milberti, CUVIER & VALENCIENNES, xv, 74, 1840, New York ; Charleston. 



Arius milberti, GUNTHER, Cat., v, 155, 1864. 



Arius eqneslris, BAIRD & GIRARD, Proc. Ac. Nat. Sci. Phila., 1855, 26, Indianola, Texas. 



Arius equestris, GUNTHER, Cat., v, 173, 1864. 



Arius felis and equestris, JORDAN & GILBERT, Synopsis, 110, 1883. 



187. HEXANEMATICHTHYS SEEMANI, (Giinther). 



Head 3|. A. 18. Head flat, depressed in front, its shields coarsely 

 granular; occipital process wider than long, with a bluntish keel; fon- 

 tanelle open to above the posterior margin of the eye, with a deep back- 

 ward extending groove ; barbels reaching slightly beyond base of pectorals; 

 vomerine teeth in 2 small ovate patches ; each joined to a larger palatine 

 patch; axillary pore large; gill rakers 5 -f- 12. Paired fins dusky within. 

 Panama. (Named for Dr. Seeman, who obtained the type.) 



Arius seemani, GUNTHER, Cat., v, 147, 1864, "Central America." 

 Tachisurus seemani, EIGENMANN, S. A. Nematognathi, 78, 1890. 



188. HEXANEMATICHTHYS JORDANI, (Eigenmann & Eigenmann.) 



Head 3. A. 18. Rather robust; interorbital area flat and smooth; 

 shields of head finely and sparsely granular ; opercle smooth ; occipital 

 process about as long as head, with an unusually sharp keel; fontanelle 



