1870.] '*"< [Cope, 



78. Ahiurus lynx,* Girard. 



This is a variable species in tlie size of the orbits and width of the head. 

 In the younger of six inches in lengtli, tlie diameter of the former is con- 

 tained in tlie interorbital space three times; in specimens of 9.5 inches 

 four times; up to tliis size the widtli of the liead enters the lengtli with- 

 out the caudal 4.5 times. Between this size and eleven inches the width 

 of the head varies from 4.5 to four times; the orbit being one-fifth the 

 frontal Avidth in those of larger size. This is the greatest relative width 

 of head I have seen in this species. Tlie upper jaw always projects below 

 the upper, the humeral process is always rugose and swollen proximally, 

 and the maxillary barbels pale edged below. 



The younger forms described, are the Ictalurus kemnsMi of Stauffer, 

 (Mombert's History of Lancaster County, Pa., 1869, 578). The following 

 description applies to such. 



It has the narrow head, large eye and furcate tail of Ictalurus. The 

 dorsal spinels nearly smooth, other rays 6 ; A. 22 ; V. 8 ; C. VI — 17 — VII* 

 The depth enters the length times. The largest specimen of this spe- 

 cies I have seen does not exceed eight inches in length. The color above 

 is a lively brown, sometimes tinged with purple; sides silvery, belly silver 

 A\ hite. 



The larger form with relatively smaller eye is I. macaskeyi, Stauffer, of 

 the same work. The same form I took in the Mispillion Creek, Dela- 

 ware. It differs from old examples of the latter in its more slender form, 

 the width of the head entering the length 4.66 times between orbits ; bar- 

 bels and color as in A. lynx. Specimens intermediate in character be- 

 tween this and the Avider-headed form served as Girard's types. They 

 were from the Potomac. Two specimens in my possession from that river 

 have tlie with head 4.25 times in length, eye 4 — 4.5 times between orbits ; 

 long maxillary, short mental barbels ; dorsal nearly equidistant between 

 muzzle and adipose ; humeral jirocess SAvollen, rugose. 



One specimen from the Susquehanna exhibits the width of the head 

 one-fourth the length, as above mentioned. This renders the distinction 

 of Girard's A. mdpeculus, questionable, since the only essential charac- 

 ters he mentions are the following: 



Head 4 times ; orbit \ ; caudal 6.5 times in length, dorsal nearer muzzle 

 than adipose fin. 



I have seen many specimens of this cat-fish from the Conestoga Creek, 

 from the Susquehanna, and from the Delaware, in Pennsylvania. 



Some specimens which I obtained at Newberne, on the Neuse River, 

 were lost, but I suspect them to have been this species. As it is common 

 in the James River, it probably occurs also in the Roanoke. 



Amiurus lopJims, Cope. 

 Species nova. 

 This, perhaps the largest species of the genus, is distinguished by the 



*In OriginofGenera,43, 1 state that the Gronias nigrilahris Cope resembles Vae Amiurus lynx most 

 closely aoiong the ^niiuri. This is an error; the comparison should be made with A.nesulosu!, 

 from which the form of the anal fin, short barbels, etc., distinguish it. 



