BULLETIN OF THE UNITED STATES FISH COMMISSION. 37 



Genus GALBIOHTHYS Cuv. & Val. 



Galeichiln/x C. & V. Hist. Nat. Poias, xv, -JO. 

 3. Galeichthys peruvianus Lutkeu. 



Galeichthya pervrianus Lutkeu, Yi<l. Medd. 1874,205 (Callao); Steindachuer, 

 [chth. Beitr. iv, :u (Altata; Panama; Callao). 



Habitat. — Pacific coast of tropical America, from Mexico to Peru; Al- 

 tata; Panama; Callao. 



No specimens of this species arc in the National Museum. 



Genus ALIUS* Cuvier & Yaleucienues. 



Arius Cuvier & Valenciennes, Hist. Nat. Poiss. xv, 53. 



Anodes, Hexanematichthys, Guiritinga, Hemiarius Cephalocassis,Netuma,Pseudarius, 

 Notarius, Anopsia, and Leptoriua of authors. 



ANALYSIS OF SI'ECIES OF ARIUS. t 



a. Bands of palatine teeth, each more or less produced backwards t on the pterygoid 



region, from the inner posterior margin or angle ; teeth 

 villiforin; vomerine bands of teeth contiguous or con- 

 fluent. (Species with coppery luster in life.) (Xctuma 

 Bleeker. ) 

 b. Ante-dorsal shield large, not crescent-shaped, its length on the median line more 



than one-tenth that of head ; vomerine bands of teeth 

 united. 

 c. Ante-dorsal shield much broader than long, its anterior margin truncate ; occip- 

 ital process very short, truncate behind; fontanelle 

 short, ending obtusely at a point much nearer tip of 

 snout than front of dorsal ; head 3£ in length. 



Alatus, 4. 

 cc. Ante-dorsal shield longer than broad, its anterior margin acute; occipital 



process short, emarginate behind ; fontanelle large, 

 ending acutely at a point nearer base of dorsal than 



tip of snout ; head 3£ Braxdti, 5. 



aa. Ante-dorsal shield small, crescent-shaped, its length on the median line much less 



than oue-tenth head. 

 d. Vomerine bands of teeth fully confluent with each other, and usually with 



the palatine bands also. 

 e. Iuterorbital area more or less uneven, ridged, or granulated. 

 /. Fontanelle obtuse posteriorly, not prolonged in a groove behind; shields 

 coarsely granular ; barbels short ; caudal less than two- 

 thirds head; head very large, 3£ in length. Kessleri, 6. 



* Some of the generic names included in the above synonymy may, perhaps, be worthy 

 of retention. All the American species examined by us are, however, in our opinion, 

 fully congeneric, although four subgenera may be recognized among them. 



\ Arius felis (L.) J. & G., the common species of the coasts of the United States, is 

 here inserted for purposes of comparison. Arius troscheli is omitted, the description of 

 the shields of the head being insufficient for comparison. 



t This character has not been verified in A. alatus; which, however, doubtless agrees 

 with A. brandti in this respect. 



