Cope] '*^^ [June 7, 



greater width of its liead, and the gape of the mouth, togetlier with the 

 decided but shallow furcation of the caudal fin. The barbels are consid- 

 erably shorter than iu any other species of the fork-tailed section. 



Head and dorsal region very flat, the width of the former contained 3.5 

 times in the length of the body and head, and the length of the same en- 

 tering the same three times. The depth at the first dorsal ray, enters the 

 same 5.4 times. That ray is exactly intermediate between the end of the 

 muzzle and the posterior mai'gin of the base of the adipose, having thus 

 a more posterior position than in A. lynx, where it measures the middle 

 of a line terminating at the anterior base of that fin. The free extremity 

 of the adijiose is in line with the same of the anal. Radii D I. 6; A. II. 

 19; V. 8. The eye is small, its long diameter entering the length of the 

 head, measured on the middle line above, seven times, and six times in 

 interorbital space. Pectoral spine weakly; dorsal not, serrate. Humeral 

 process strongly rugose to near extremity. 



Maxillary barbel reaching two-thirds to three-fourths the distance from 

 its base to the upper part of the branchial slit, the outer only half way to 

 the branchiostegal margin, the inner three-fourths the length of the outer. 

 The extremity of the muzzle is regularly rounded, the upper jaw project- 

 ing a little beyond the upper. Bi-anchiostegal rays nine. Total length 

 eighteen inches; length dorsal spine 18 lin. ; do. pectoral spine 18 lin. ; do. 

 basis of anal 35 lin. ; width of head 53 1. 



Color above brown; lower surfaces, including lower lip, (yellow or) 

 white in alcohol; mental beards white. 



This species is nearest the A. lynx, Girard, which inhabits the same 

 rivers, but is readily distinguished as above pointed out, and in addition- 

 ally, by the shorter barbels and lower body. In the width of its gape it 

 exceeds any other Xortli American cat-fish, and will allow of a remote 

 comparison with Lophius in this respect. 



I obtained three specimens in the AVashington, D. C. market, which came 

 from the lower course of the Potomac river. It occurs in the other tribii- 

 taries of the Chesapeake Bay, and I think I have seen it in the market of 

 Baltimore. I have not yet observed it in Philadelphia. In the former 

 cities it is deservedly esteemed for the table, and is more valuable than 

 the A. lynx and A. nehulosus, on account of its superior size. 



The last named fish is sold in Philadelphia and neighborliood. It often 

 attains a foot in length. I cannot distinguish the Pirn, albidus, Lesucur, 

 Pale and piebald varieties of the fisii occur. 



79. Amiurus kiveiventius, Cope. 



Spec. nov. 



This fish presents a great contrast to the last, resembling in fact the 

 Ictalurus earulescens, Raf., in its slender proportions. 



Width of head 4.75 times in length, exclusive of caudal fin. Orbit nearly 

 four times into interorbital width. Depth 5.22 in length as above. Dor- 

 sal spine three inches from end muzzle, 3.5 inches from origin adipose fin; 

 its posterior margin with a concealed sen-ation. Pectoral spine strongly 



