486 University of Kansas Geological Survey. 



much inflated ; wing moderately large, well denned at its inner 

 side by an auricular furrow ; hinge line not very long, nearly 

 at right angles with the front of the shell, and only a little ob- 

 lique with the axis ; a more or less distinct, but somewhat ir- 

 regular furrow extending the entire length of the shell from the 

 posterior side of the umbo to the postero-basal margin, giving 

 each valve an obscurely bilobed appearance ; crenulated face of 

 the hinge narrow, crenulations small ; umbonal region narrow ; 

 beaks prominent, curved forward and inward ; test compara- 

 tively thin throughout the whole shell ; surface having the or- 

 dinary concentric lines of growth, and the test is also thrown 

 into numerous, rude and irregular concentric undulations. 

 Length of the largest example in the collection, about twenty- 

 two cm. ; greatest breadth, about fifteen cm." 



This species occurs in the lowermost Ornithostoma beds of 

 the Niobrara Cretaceous. 



Inoceramus deformis Meek. Plate xcn, fig. 2. 



Inoceramus deformis Meek, 1871, Ann. Rep. U. S. Geol. Surv. Terr, for 

 1870, p. 296; White, 1876, U. S. Geol. and Geog. Surv. West 100th Mer., 

 vol. iv, p. 179, pi. xv, If. la, b; Meek, 1877, U. S. Geol. Surv. Expl. 40th 

 Par., vol. iv, pt. i, p. 146, pi. xiv, ff. 4, 4a; Stanton, 1893, Bull. U. S. Geol. 

 Surv. No. 106, p. 85, pi. xiv, f. 1, pi. xv. ff. 1, 2. 



Haploscapha capax Conrad, 1874, Ann. Rep. U. S. Geol. Surv. Terr, for 

 1873, p. 456. 



/Haploscapha deformis White, 1876, U. S. Geol. and Geog. Surv. Terr., vol. 

 ii, pp. 23, 24, pis. lxvi, lxvii. 



Inoceramus f Hall, 1845, Fremont's Rep. Expl. Rocky Mts., p. 310, 



pi. iv. f. 2. 



Meek's description: "Shell attaining rather large size, ob- 

 liquely ovate, and rather compressed in young examples, but 

 more rounded, gibbous, and irregular, as well as much less ob- 

 lique, in adult specimens ; more or less inequivalve, but never 

 very decidedly so ; posterior and basal margins rounded ; the 

 latter curving up more gradually and obliquely to the short an- 

 terior margin ; hinge short and usually not very oblique ; beaks 

 moderately prominent, and placed between the middle and an- 

 terior margin ; neither greatly more elevated than the other. 

 Surface ornamented with large, strong concentric undulations, 

 which are sometimes moderately regular but often very irregu- 



