506 University of Kansas Geological Survey. 



Inoceramus sagensis, var. nebrascensis Owen. Plate cix, fig. 2. 



Tnoceramus nebrascensis Owen, 1852, Rep. Minn., Iowa, and Wis., 582, 



pi. viii, f. 1. 

 Inoceramus sagensis Owen, 1852, ibid., pi. vn, f. 3. 

 Inoceramus sagensis, var. nebrascensis, Meek, 1876, U. S. Geol. Surv. 



Terr., pi. xm, ff. 2a, b. 



Description: "Shell large, obliquely broad ovate or subcir- 

 cular, moderately gibbous, about as high as long ; anterior side 

 short, making a very broad oblique curve from the beaks to the 

 base ; ventral and postero-ventral margins nearly regularly 

 rounded ; hinge rather short, forming an angle of about fifty 

 degrees with the axis of the umbones ; beaks moderately con- 

 vex, rising little above the hinge, oblique, scarcely incurved, 

 located about one-fifth the horizontal diameter (length) of the 

 shell behind the anterior border. Surface ornamented by reg- 

 ular, distinct, concentric undulations. Length, about five and 

 seventy-hundredths inches ; height, five and sixty-hundredths 

 inches. These measurements are taken from a medium-sized 

 specimen/' 



After a comparison of specimens Meek concludes that Inocera- 

 mus nebrascensis Owen is but a variety of Inoceramus sagensis 

 Owen. The specimen in the University collection was collected 

 by Prof. B. F. Mudge, from the Butte creek Fort Pierre shales, 

 and is a smaller specimen than that described by Meek. 



Inoceramus altus Meek. Plate cvn, fig. 1. 



Inoceramus nltus Meek, 1878, Hayden's Rep. Geol. Surv. Terr., 302; 1876, 

 U. S. Geol. Surv. Terr., vol. ix, pi. xiv, ff. la, b. 



Meek's description : " Shell attaining a medium size, verti- 

 cally or a little obliquely subovate, being in the adult higher 

 than long, and widening from the hinge downward, moderately 

 convex, equivalve, very inequilateral ; hinge very short and 

 ranging nearly at right angles to the longer axis in the adult, 

 but a little more oblique in young shells ; anterior side straight, 

 long, and truncated vertically, or nearly at right angles to the 

 hinge, immediately in front of the beaks ; base regularly 

 rounded ; posterior outline forming a broad, somewhat oblique, 

 gentle curve from the posterior end of the hinge into the base ; 



