96 CONTEIBUTIOXS TO NORTH AMERICAN ICUTHYOLOGY II. 



Genus NOTUEUS, Bafinesque. 



Noturu8,^\v. (1818), Am. Monthly Mag. and Crit. Eev. iv, Nov. 41, and of most subse- 

 quent authors. 

 ScMlbeodes, Bleeker (1858), "Ichthyologiao Archipelagi Indict Prodromus, vol. i. Siluri 

 (Acta Societarum Indo-Nederlandicse, vol. iv.) 258, (*S. gyrinus Mit.)." (Also 

 written Schilbeoides ; I do not know which is the original orthography.) 

 Etymloogy. — vuTog, back; ovpa, tail (" means tail over the back", Eaf,). 

 Type. — Noturus fiavus Eaf. 



Body more or less elongate, anteriorly sabcylindrical, 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 ScMl- 

 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 halt 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 ventrals are rounded, and each has one simple and eight branched 

 rays. • 



