104 COLORADO FORMATION AND ITS INVERTEBRATE FAUNA, [bull.106. 



have the pallial line sinuous. The sinus, however, is usually shallow 

 and rounded, or obtuse, in our fossil species; that of the shell here 

 under consideration being unusually deep and angular. 



"Locality and position. — Near Missouri river, below Gallatin city, 

 Montana, where it occurs, associated with Trigonia, Inoceramus, Car- 

 dium, Ostrea, and other marine Cretaceous fossils.' 1 



CYPRINIDyE. 



(ienus VKXIELLA Stoliczka. 



Venieela mortoni M. & IT. 



PI. xxin, Figs. 6-9. 



Yen'rfia morion i Meek and Hayden, IS(!2, Proc. Acad. Nat. Sci. Phila., p. 27. 

 Veniella mortoni Meek, 1876, U. S. Geol. Bnr. Terr., vol. ix, p. 151, Fl. 4, Figs. 3a, b. 



Revised description : 



a Shell transversely oblong, or subtrapezoidal in outline, gibbous, 

 thick, and strong; base nearly straight, but rounding up in front; 

 dorsal margin parallel to the base, excepting where it declines, at first 

 gently, then abruptly, into the obliquely-truncated posterior; anterior 

 side truncated vertically immediately in front of the beaks, just below 

 which there is a slight sinuosity of outline, as seen in a side view; 

 posterior basal extremity narrowly rounded, or subangular; beaks very 

 oblique, strongly incurved, gibbous, and placed directly over the ante- 

 rior; umbonal slopes forming a prominent, rather angular, oblique 

 ridge, from each beak to the posterior basal extremity; lunule and 

 escutcheon impressed, but without strongly defined margins; surface 

 marked with distinct concentric stria*, and stronger, irregular ridges, 

 the latter of which sometimes pass into regular, rather distant, low 

 varices on the umbones. 



"Length, 1.66 inches; height, 1.40 inches; convexity, 1.17 inches. 



"This species is nearly related, at least in external characters, to V. 

 Conradi Morton, but differs in being more oblique and more depressed 

 at the beaks, which are also placed directly over the more truncated 

 anterior margin. Its dorsal margin is also longer and less sloping than 

 in Mortonjs species. It will be more readily distinguished from the 

 last by its greater proportional length, less angular umbonal slopes, 

 and rougher surface. 



"I have not seen the hinge of this species; but from its form and 

 general external appearance, there is little reason for doubting that it 

 belongs to the genus under which it is placed. 



"Locality and position. — Chippewa point, on the upper Missouri, near 

 Fort Benton ; from the Fort Benton group of the Cretaceous." 



The specimens that are figured on PI. xxin came from the upper 

 part of the Fort Benton shales on the Arkansas river, 20 miles west of 



