"Skin naked, or with osseous scutes, but without scales. Barbels always present; maxillary bone rudimentary, margin of the upper jaw formed by the premaxillaries only. Suboperculum absent; adipose fin present or absent." (Günther.)
RHINEASTES, Cope.
U. S. Geol. Survey of the Terrs., 1872, p. 638.
A genus allied to the recent Ichtælurus but differing in the inferior grooving of the vertebræ and in the rough exostoses of the cranial bones. It differs from Phareodon in having the usual band of bristle-like teeth on the dentary.
Rhineastes —— ?
Represented by a portion of the dentary and hyomandibular bones of a large cat-fish from Bridger Butte.
The dentary is broad and shallow, grooved below, and deeply striated on the external face. As much of it as is preserved is straight. The teeth are small, subequal throughout, and very numerous. The hyomandibular is broad and thick, and has a striated surface. The condyle is peculiar in having two separate articular faces above and below, one convex and the other flat.
GANOIDEI.
CYCLOGANOIDEI.