68 BRACHIOPODS. 



Orthis riehmonda McChesney, 1860: Desc. New Palae. FOBS. , p. 32. 

 Hemipronites crassus Meek & Hay den, 1864 : Palae. Upper Missouri, p. 26, 



pi. i, figs. 7a-d. 

 Orthis crenistria Geinitz, 1866: Garb, und Dyas in Nebraska, p. 46, tab. 



iii, figs. 20, 21. 

 Hemipronites lasallensis McChesney, 1867 : Trans. Ghicago Acad. Sci., vol. 



I, p. 28, pi. i, fig. 6. 

 Hemipronites crassus McChesney, 1867: Trans. Chicago Acad. Sci., vol. 



I, p. 28, pi. i, fig. 5. 

 Hemipronites crassus Meek, 1872: U. S. Geol. Sur. Nebraska, p. 174, pi. 



v, figs. lOa-b; and pi. viii, fig. 1. 

 Hemipronites crassus Meek & Worthen, 1873: Geol. Sur. Illinois, vol. V, 



p. 570, pi. xxv, fig. 12. 

 Hemipronites crenistria White, 1875 : U.S. Geog. Sur. w. 100 Merid. , vol. 



IV, p. 124, pi. x, fig. 9a. 

 Hemipronites crassus White, 1884: Geol. Sur. Indiana, Rep. 1883, p. 129, 



pi. xxvi, figs. 4-11. 

 Streptorhynchus crenistria Keyes, 1888: Proc. Acad. Nat. Sci., Phila , 



p. 229. 



Shell quite variable, semi-circular to nearly round in out- 

 line, generally, however, considerably wider than long: hinge- 

 line usually shorter than the greatest breadth of the valves. 

 Dorsal valve moderately convex ; beak not distinct. Ventral 

 valve convex at first, but becoming flat and then sometimes 

 concave around the anterior margin ; hinge-area varying con- 

 siderably in height; plane ! or slightly concave, more or less 

 distinctly marked by fine lines ; foramen closed. Surface 

 ornamented by numerous fine radiating ribs, of which every 

 fourth or fifth is much more prominent than the rest ; these 

 are crossed by fine lines of growth. 



Horizon and localities. Upper Carboniferous, Coal Meas- 

 ures : Kansas City, Clinton, Lexington. 



Meekella striatocostata (Cox) 



Plate xxxix, figs. la-c. 



Plicatula striatocostata Cox, 1857: Geol. Sur. Kentucky, vol. Ill, p. 568, 

 pi. viii, fig. 7. 



Orthisina shumardiana Swallow, 1858: Trans. St. Louis Acad. Sci., vol. 

 I, p. 183. 



Orthisina missouriensis Swallow, 1858: Trans. St. Louis Acad. Sci., vol. 

 I, p. 219. 



Streptorhynchus pyramidalis Newberry, 1861 : Ives' Exp. Exped. Colorado- 

 River, p. 126 



