40 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



vomerine baud by a narrow toothless line: in old specimens the vomerine 

 and palatine bands are wholly confluent ; each palatine band with a 

 narrow backward prolongation on the median line. Baud of preinax- 

 illary teeth broad, about six times as long as wide. Lower jaw in- 

 cluded. • 



Maxillary barbel nearly or quite reaching gill-opening. Outer mental 

 barbels about two-fifths head; the inner nearly four-fifths. 



Aute-dorsal plate much larger than usual in this genus, shaped like 

 an armorial-shield, its posterior margin concave, its anterior end acute, 

 wedged into a deep emargination of the occipital process, the two be- 

 coming co-ossified with age. Length of ante-dorsal plate on the median 

 line 5 to 6 in head, a little more than its width ; occipital process short 

 and broad, much broader than long ; its median line with a broad keel, 

 its edges nearly straight. Shields all coarsely granular, the granula- 

 tions anteriorly forming radiating strise. 



Foutanelle large, claviform, broadest posteriorly, its posterior end 

 about midway between tip of snout and front of dorsal ; its greatest 

 breadth about equal to the diameter of the eye and one-sixth its length; 

 a short groove extending backward from its obtuse tip ; sides of fonta- 

 nels bony and granulated for its whole length, the granules extending 

 forward to opposite nostrils. 



Dorsal spine strong, If in head, moderately compressed; pectoral 

 spine If in head. Axillary pore obsolete. Humeral process coarse, gran- 

 ular, broad, nearly half length of pectoral spine. Base of adipose fin 

 scarcely two-thirds length of anal, its posterior margin little free. Cau- 

 dal deeply lunate, small, its upper lobe slightly the longest and nar- 

 rowest, If in head. Ventrals not quite reaching anal ; *vent much nearer 

 base of ventrals than anal. 



Dark brown, with strong bronze luster above, white below ; dorsal 

 dusky, especially above ; pectorals blackish ; anal dark ; caudal rather 

 pale; ventrals usually dark towards the tip, their inner side pale; 

 maxillary barbel dusky ; mental barbels pale. 



This species is not rare along the Pacific coast of tropical America, 

 specimens having been observed at Mazatlan, Puuta Arenas, and 

 Panama. At Mazatlan, it is known as "Bagre Colorado", and is said 

 to reach a larger size than any other of the Cat-fishes. It is used for 

 food. 



SPECIMENS IN UNITED STATES NATIONAL MUSEUM. 



28230. Mazatlan. Gilbert. 

 29254. Mazatlan. Gilbert. 

 29262. Panama. Gilbert. 



6. Arius kessleri Bteiudacbner. 



Arius keasleri Steindachner, Ichth. Beitrage, iv, 24, 1875, taf. v (Altata; 

 Panama). 



Habitat. — Pacific coast of tropical America; Altata; Panama. 



