CHAPTER XI. 



BRACHIOPODS. 

 Lingula umbonata Cox. 



Plate xxxv, fig. 4. 

 Lingula umbonata Cox , 1857: Geol. Sur. Kentucky, vol. Ill, p. 576, pl.x, 



fig. 4. 

 Lingula carbonaria Shumard, 1858: Trans. St. Louis Acad. Sci., vol. I, 



p. 215. 

 Lingula mytiloides Meek & Worthen, 1873: Geol. Sur. Illinois, vol. V, p. 



572, pi. xxv, fig. 12. (Not Sowerby, 1813). 

 Lingula umbonata White, 1884: Geol. Sur. Indiana, 13th Ann. Kept., pt. 



ii, p. 12Q, pi. xxv, fig. 14. 

 Lingula umbonata Keyes, 1888: Proc. Acad. Nat. Sci., Phila., p. 226. 



Shell thin, elliptical, sightly convex, wider in front than 

 back of the middle, margins regularly rounding, rather sharply 

 on the posterior border ; umbo rather prominent ; beak small. 



Horizon and localities Upper Carboniferous, Coal Meas- 

 ures: Clinton (Henry county), Kansas City. 



Lingulella lamborni MEEK. 

 Plate xxxv, figs 5a-d. 



Lingulella lamborni Meek, 1871 : Proc. Acad. Nat. Sci., Phila., p. 185, figs. 

 1-4. 



Shell small, compressed, broadly subovate, about one-fifth 

 longer than wide. Ventral valve pointed at the beak, from 

 which the nearly straight lateral slopes diverge at an angle of 

 about 35, to near the middle of each lateral margin, then reg- 

 ularly rounding forward ; false cardinal area well developed 

 and extending back, with the beak nearly one-fourth the length 

 of the valve, behind that of the other valve, and having its 

 mesial furrow for the peduncle well-defined, on each side of 

 which is a diverging longitudinal line extending from the apex 

 of the beak, so as to form the margins of the false area, which 



