FAMILY SILURID^ — ARIUS. 179 



under the adipose dorsal, and with twenty-three rays. Caudal deeply lunate ; its tips acute, 

 and its lobes occasionally unequal. 



Color. Blue above, tinged with green ; sides silvery ; abdomen opaque white. 



Length, 19-0. 



Fin rays, D. 1.7; P. 1.12; V.6; A. 23 ; C. 17. 



This marine Cat-fish has a wide geographical range, having been found in the Atlantic from 

 23° south to 41° north latitude, along the shores of the two Americas. Its flesh has been 

 represented to me by those who have eaten of it, as having an exquisite flavor. It is fre- 

 quently abundant in Communipaw creek, on the Jersey side of the harbor of New- York. It 

 swims frequently with its long dorsal above the surface, in the manner of sharks, and imitat- 

 ing those animals in voracity. 



In accordance with the law of priority, I have restored the original name given by Dr. 

 Mitchill, although unmeaning. It is not preoccupied in this genus. 



GENUS ARIUS. Cuvier. 



With the general form of the preceding, hut the palatine teeth form two distinct and distant 

 •plates ; rarely any on the vomer. Branchial rays five or six. 



Obs. This genus, recently separated from Bagrus, and forming a passage to the genus 

 Pimelodus, now comprises about forty species, chiefly from Asia, Africa, and the southern 

 parts of America. They may be subdivided into those which have acute card-like teeth, and 

 those in which they are so closely approximated and rounded as to appear paved. To the first 

 division belongs 



MILBERT'S ARIUS. 



Arids milbebti. 

 L'Amu de Milbert. Cnv. et Val. HisL des Poiss. Vol. 15, p. 74. 



Characteristics. Casque granulated all over, and not in radiating striae. Length five to fifteen 

 inches. 



Description. Head one-fifth of the total length. Snout round ; its casque granulated as far 

 as between the eyes. A narrow slit ascends half way up the casque. The interparietal pro- 

 cess is one-third the length of the remaining part of the head. Its base equals its length ; 

 truncated at the end by the crescent of the buckler, which is itself truncated anteriorly. The 

 granulations are equal, distinct but not large. Front and sides of the head smooth. The 

 humerus with a smooth skin. The prominence of the upper jaw not very great. Palatine 

 teeth on two oval plates, nearly touching in front by a small point. The maxillary cirri 

 or barbels extend slightly beyond the end of the opercle ; the external submandibulary cirri 

 a fourth less. The spines moderate, with feeble teeth towards the tips, both in front and 



