STANTON.] 



LIMIDJE. 71 



LIMID^E. 

 Genus LIMA Brugui6re. 

 Lima utahensis n. sp. 

 PL ix. Fig. 5. 



Lima wacoensis White, 1876, U. S.Geog.& Geol. Expl. West 100th Meridian, vol. IV, 



p. 176, PL 17, Figs. 4a, b, and c. 

 Not Lima wacoensis Roem., 1852, Kreide. von Texas, p,63, PI. 8, Fig. la, b. 



Dr. White's description is as follows : 



"Shell rather small, moderately convex, oblique, irregularly oval in 

 marginal outline; antero-basal margin broadly rounded; posterior mar- 

 gin regularly, but more shortly rounded than the base; front margin 

 subtruncate; postero-dorsal margin nearly straight or slightly convex, 

 and nearly parallel with the antero-basal margin; hinge short; ears of 

 about equal size, small, but distinct, each forming an obtuse angle by 

 the cardinal border, and the anterior and posterior borders respec- 

 tively; beaks small, distinctly defined, projecting a very little over the 

 cardinal border. Surface marked by numerous radiating costse, which 

 have interspaces of similar or slightly greater width between them; 

 cosiae becoming smaller upon each side of the umbonal region, and 

 absent from the ears. 



" The long diameter of the largest example contained in the collec- 

 tions is about 17"""; short diameter, 14 rn, ".' ? 



Comparison of the Utah specimens above described with examples 

 of Koemer's species from Texas shows that they are specifically dis- 

 tinct. Lima utahensis differs from L. wacoensis in the following par- 

 ticulars: In form it is considerably less oblique and proportionally 

 more ventricose; the radiating costee are more slender and less angu- 

 lated, more uniform in size, more regularly arranged, and they never 

 bifurcate in any of the specimens examined; it is a somewhat smaller 

 species, though the valve now figured measures about one-fifth more 

 than the dimensions above given. 



The fact that Lima wacoensis occurs in the Comanche series associated 

 with a fauna that is entirely distinct from that in which L. utahensis 

 occurs is an additional reason for their separation. 



Locality and position. — The types are from " southeast of Paria, 

 Utah." The specimen figured in this bulletin was collected by Mr. C. 

 I). Walcott in Upper Kanab valley, about 350 feet above the base of 

 the Cretaceous section there. 



