450 University of Kansas Geological Survey. 



Inoceramus fragilis M. & H. Plate lxxxvii. 



Inoceramus fragilis H. & M., 1856, Mem. Am. Acad. Arts and Sci., n. s., vol. 

 v, p. 388, pi. ii, ff. 6a and b ; White, 1876, U. S. Geog. and Geol. Surv. West 

 100th Mer., vol. iv, p. 178, pi. xv, f. 3; Meek, 1876, U. S. Geol. Surv. Terr., 

 vol. ix, p. 42, ff. 1 and 2 in text and pi. v, f. 5; Meek, 1876, Macomb's Ex- 

 pedition from Santa Fe to Junction of the Grand and Green Rivers, Geol. 

 Rep., p. 127, pi. i, f. 6; Whitfield, 1880, Geol. Black Hills of Dak., p. 390, 

 pi. ix, f. 10; Stanton, 1892, Bull. U. S. Geol. Surv. No. 106, p. 76, pi. xi, ff. 1-5. 



Inoceramus howelli White, 1876, Geol. Uinta Mts., p. 114; 1879, 11th Ann. 

 Rep. U. S. Geol. Surv. Terr., p. 284, pi. iv., ff. la, b, c. 



Inoceramus perplexus Whitfield, 1880, Geol. Black Hills of Dakota, p. 392, 

 pi. vin, f. 3, and pi. x, ff. 4 and 5. 



Revised description: "Shell moderately thin, broadly sub- 

 ovate, higher than long, moderately convex; subequivalve ; 

 anterior side vertically truncate from the beaks, with slightly 

 concave outline ; basal and posterior borders forming a more or 

 less regular, nearly semicircular curve ; hinge line rather short, 

 and standing at right angles to the truncate anterior. Beaks 

 pointed, equal, scarcely rising above the hinge, curving inward 

 and slightly forward at the points. Surface marked by fine 

 lines of growth and a few obscure traces of concentric undula- 

 tions. Height of an average specimen, thirty-five mm. ; length, 

 twenty-six mm." 



This species occurs in the Fort Benton limestone and also in 

 the Septaria horizon. 



Inoceramus labia t us Schlotheim. Plate xcn, fig. 4. 



Ostracites labiatus Schloth., 1813, Bronns Jahrb., vol. vn, p. 93. 

 Mytulites problematicus Schloth., 1820, Petrefactenk. i, p. 302. 

 Inoceramus mytiloides Mantell, 1822, Geol. of Sussex, p. 215, pi. xxvn, f. 2; 



Roem., 1852, Kreid. von Texas, p. 6G, pi. vn, f. 5. 

 ? Inoceramus confertlm-annulatus Schiel, 1855, Pac. R. R. Reps., vol. n, 



pi. ii, f. 7. 

 f Inoceramus pseudo-mytiloides Schiel, 1855, ibid., pi. in, f. 5. 

 Inoceramus mytilopsis Conrad, 1857, U. S. Bound. Surv., vol. i, p. 152, pi. n, 



ff. 6a and 6b. 

 Inoceramus problematicus (Schloth.) Meek, 1876, U. S. Geol. Surv. Terr., 



vol. ix, p. 62, pi. ix, ff. 3a and b. 

 Inoceramus aviculoides M. & H., 1860, Proc. Acad. Nat. Sci. Phil., p. 181. 

 Inoceramus problematicus var. aviculoides Meek, 1876, U. S. Geol. Surv. 



Terr., vol. ix, p. 63, pi. ix, f. 4. 



Inoceramus labiatus Stanton, 1892, Bull. U. S. Geol. Surv., p. 77, pi. x, f. 4; 

 pi. xiv, f. 2. 



Meek's description: "Shell obliquely elongate-oval, sub- 

 elliptical or ovate, nearly or quite equivalve, rather com- 



