1870.] 487 
[Cope. 
78. AmM1uRUS LyNx,* Girard. 
This is a variable species in the size of the orbits and width of the head. 
In the younger of six inches in length, the diameter of the former is con- 
tained in the interorbital space three times; in specimens of 9.5 inches 
four times ; up to this size the width of the head enters the length 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 width in those of larger size. This is the greatest relative width 
of head I have seen in this species. The 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 kevinskti 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 Ictwlurus. The 
dorsal spine is 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 
white. 
The larger form with relatively smaller eye is I. macaskeyi, Stauffer, of 
the sume work. The same form I took in the Mispillion Creek, Dela- 
ware. It differs from old examples of the A. lynz 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. lynw. Specimens intermediate in character be- 
tween this and the wider-headed form served as Girard’s types. They 
were from the Potomac. Two specimens in my possession from that river 
have the 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 process swollen, 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. vulpeculus, questionable, since the only essential characters 
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 lophius, Cope. 
Species nova. 
This, perhaps the largest species of the genus, is distinguished by the 
* In Origin of Genera, 43, I state that the Groniae nigrilabris Cope resembles the Amiurus 
lynx most closely among the Amiuri. This is an error; the comparison should be made with 
A. nebulo«ue, from which the form of the anal fin, short barbels, ete. distinguish it. 
