The Fauna of the Maxinlle Limestone. 387 



1895. Enmetria vera var. costata. Hall and Clarke, Pal. N. Y., Vol. VIIl, 

 pt. II, pi. 51, figs. ^T-S.S. 

 Chester limestone : Crittenden County, Kentucky ; Chester, Illinois. 

 1895. Eiiinctna vera. Hall and Clarke, Pal. N. Y., Vol. VIII, pt. II, 

 pi. 51, figs. 36, 37. 

 Chester group : Crittenden County, Kentucky. 

 1895. Einiiefria Verneidliana. Hall and Clarke, Pal. N. Y., Vol. VIII, 

 pt. II, p. 117, figs. 104, 105, pi. 51, figs. 13-26, 34, 35, pi. 83, 

 figs. 26, 27. 

 St. Louis group : Spergen Hill, Indiana ; Green County, Missouri. 

 1897. Euimtria.verneuUana. Weller, Trans. N. Y. Acad. Sci., Vol. XVI, 

 p. 259. , . . . - 

 Batesville sandstone: Batesville, Arkansas. 

 1899. Enmetria T'enicuiliaua. Girty, U. S. Geol. Surv., Mon. 32, pt. II, 

 p. 560, pi. 68, figs. 12a-r2b. 

 Madison limestone : Yellowstone National Park. 



1903. Enmetria marryi? Girty, U. S. Geol. Sui-v., Prof. Paper 16, p. 303 

 Ouray limestone : San Juan region, Colorado. 



1904. Enmetria marcyi. Girty, U. S. Geol. Surv., Prof. Paper 21, p. 49, 



pi. 10, figs. 15-17. 

 Mississippian CEscabrosa limestone) : Bisbee quadrangle, Arizona. 

 1906. Enmetria marcyi. Beede, Ind. Dept. Geol. Nat. Res., 30th Ann. 

 Rep., p. 1319, pi. 22, figs. 28-30. 

 Salem limestone : Spergen Hill, etc., Indiana. 

 1909. Enmetria marcyi. Grabau and Shimer, N. A. Index Foss., p. 340, 

 fig. 444 d, e.. 

 St, Louis and Kaskaskia ; Tennessee, Missouri, Arkansas, In- 

 diana, Iowa, Illinois. 

 1911. Enmetria marcyi. Girty, U. S. Geol. Surv., Bull. 439, p. 77, pi. 8, 

 fig. 10. 

 Moorefield shale: Batesville quadrangle, Arizona. 



Description. — Shell very variable, ranging from smaller 

 than mediinn to medium size, longitudinally ovate, almost equally 

 biconvex. 



Pedicle valve most convex in the umbonal region. Beak 

 large, elevated, incurved, truncated by a nearly vertical plane, 

 which produces a large rounded foramen. 



Brachial valve more circular in outline with a small incurved 

 "beak. 



