SILURIDA. — 71 
following synopsis. A Chinese species, Pimelodus cantonensis, referred 
by Dr. Giinther to Amiurus, is excluded, as its real position is perhaps 
uncertain. The species are most abundant in the Mississippi Valley 
and Great Lake Region. Some of them occur in all our waters east of 
the Rocky Mountains, but as yet none are known from the Pacific 
Slope. 
ANALYSIS OF THE GENERA OF ICHTHAZLURI. 
* Adipose fin with its posterior margin free, not connected with the caudal fin: 
t. Intermaxillary band of teeth convex in front, abruptly truncate behind, without 
lateral backward processes; branchiostegals 8 or 9 (rarely 10 or 11); ventral fins 
normally with 8 rays: 
ft. Supraoccipital bone prolonged backward, its apex emarginate, receiving the 
pointed anterior end of the second interspinal, thus forming a continuous bony 
bridge from the snout to the base of the dorsal; branchiostegals 8 or 9; head - 
elongate; mouth small, terminal, the upper jaw thelonger; anal fin elongate, 
of 24 to 34 rays; caudal fin furcate; body elongate, more or less slender, sil- 
Vey COvered svilulit hime scl years eeserslse ose tne ees aera ICHTHALURUS. 
tf. Supraoccipital bone free behind, not connected with the interspinal ; branchi- 
ostegals normally 9 (varying from 8 to11); head broad; mouth broad, terminal ; 
anal fin moderate or rather long, with 15 to 27 rays; caudal fin usually truncate, 
but offen more or less deeply emarginate or even forked ; body usually more or 
less shortened, covered with a rather thick skin... .----.---.......-. AMIURUS. 
tt. Intermaxillary band of teeth convex. in front, with a lateral backward extension 
on each side; branchiostegals normally 12; supraoccipital bone free behind ; 
head long, broad, and flat ; mouth large, the lower jaw always the longer; anal 
fin short, of 12 to 14 rays; ventrals with 9 rays; caudal fin truncate, its numerous 
rudimentary rays recurrent above and below the caudal peduncle; number of 
vertebrae increased; body elongate, covered with thick skin....PELODICHTHYS. 
**, Adipose fin long and low, keel-like, adnate to the back, more or less perfectly con- 
tinuous with the caudal fin; supraoccipital bone free behind; branchiostegals 
9; anal fin short, with 11 to 20 rays; caudal fin rounded, with numerous rudi- 
mentary rays recurrent on the caudal peduncle; ventral rays usually 9; form 
various, but body usually more or less elongate, depressed in front, compressed 
behind, covered with a thickish but semi-transparent skin; size small, NoruRus. 
CATALOGUE OF NOMINAL SPECIES, WITH IDENTIFICATIONS. 
In the following list are given, in chronological order, the names thus 
far proposed for our fresh-water Siluridew. In the right-hand column is 
my identification of each species. Those species of which I have ex- 
. . . . U 
amined the original types are designated by a star (*). 
Nominal species. - Daie. Identification. 
DMUs EC HU Syl cts eee fe eee 1758 | Amiurus catus. 
Slums yrinns, Vibe see eee eee ee 1317 | Noturus gyrinus. 
Silurus;punctatus, Rat 22.25. -2522- -a.--- 1818 | Ichthelurus punctatus. 
Sid honators) AVA IANSH INES ois ad Gase ese ep oceuioe = 1818 | Pelodi-hthys olivaris. 
PNOLUDUS MIA VIS hati: Soe yee ee oe tire 1818 | Noturus flavus. 
