96 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY—II. 
Genus NOTURUS, Rafinesque. 
Noturus, Rar. (1818), Am. Monthly Mag. and Crit. Rev. iv, Nov. 41, and of most subse- 
quent authors. 
Schilbeodes, BLEEKER (1858), ‘‘ Ichthyologie Archipelagi Indici Prodromus, vol. i. Siluri 
(Acta Societarum Indo-Nederlandice, vol. iv.) 255, (S. gyrinus Mit.).” (Also 
written Schilbeoides ; I do not know which is the original orthography.) 
ETYMLOOGY.—voroc, back; ovpa, tail (‘‘ means tail over the back”, Raf.). 
Typr.—Noturus flavus Raf. 
Body more or less elongate, anteriorly subcylindrical, thence more or 
less compressed. 
Head above ovate and depressed, with a slight longitudinal furrow, 
branching into a transverse depression on the nape. Skin very thick, 
entirely concealing the bones. Supraoccipital entirely free from the 
head of the second interspinal. Eyes small or of moderate size. Mouth 
anterior, rather large, and transverse. Upper jaw usually more: or 
less projecting beyond the lower. Teeth subulate, closely aggregated 
in a broad band in each jaw, which in the lower one is interrupted by 
a linear interval and in the upper one is continuous. The band in the 
upper jaw is either abruptly truncated at each end (subgenus Schil- 
beodes) or prolonged backward by a continuation from the postero- 
external angle (subgenus Noturus). The lower band is, as usual, at- 
tenuated toward the corners of the mouth. Branchiostegal membrane 
with nine rays on each side. 
Dorsal fin situated over the posterior half of the interval between 
the pectoral and ventral fins, with a very pungent, short, edentulous 
spine and seven branched rays. 
Adipose fin long and low, connected with the accessory rays of the 
caudal fin, and not forming a separate fin, never free behind; the mem- 
brane sometimes high and continuous, sometimes notched, in one spe- 
cies to the base. 
Caudal fin very obliquely truncated or rounded, and inserted on an 
equally obliquely rounded base. The rays rapidly decrease in length 
inferiorly, and there are numerous rudimentary ones both above the 
caudal peduncle, where the anterior is united to the adipose fin, and 
forms a continuous keel (interrupted in one species), and below, where 
they advance considerably forward. 
The anal fin is comparatively short, and rapidly increases in height 
for the first half of its length. It has from 12 to 20 rays. 
The veutrals are rounded, and each has one simple and eight branched 
rays. 
