428 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



usually occupied by four plications. The sinus on the pedicle valve is broad, not very 

 deep, and is occupied usually by three plications. The lateral plications vary from 

 seven to nine. Sometimes six occupy the median fold. The shell is greatly thick- 

 ened interiorly, especially around the deep muscular scar in the pedicle valve. 



Occurrence. — Maysville group: Bellevue, Madison, and numerous 

 other localities in Indiana; Oldham County, Kentucky. Leipers: 

 Stockett Hill, White Creek post office, Leipers Creek, etc., Tennessee, 

 Bellevue, Cincinnati, and numerous localities in Ohio. 



PLATYSTROPHIA PONDEROSA AUBURNENSIS Foerste. 



Plate 49, figs. 9-12. 



I'latystrophia poaderosa auburnensls Foerste, Bull. Sci. Lab. Denison I'niv., 



vol. 14, 1909, p. 226, pi. 4, fig. 15. 

 Orthis (Platystrophia) biforata var. lynx Meek, Pal. Ohio, vol. 1, 1S73, p. 144, pi. 



10, fig. 1.— Lesley, Geol. Surv. Penna., Kept. P. 4, 1889, p. 509. 

 Delthyris lynx Hall, Pal. New York, vol. 1, 1S47, pi. 32Z), figs. lA, B. 

 I'latystrophia biforata var. lyyix Hall and Clarke, Pal. New York, vdl. lo, pt. 1, 



1892, pp. 202. 22.3, pi. 55, figs. 1-4. 

 Platystrophia lynx Cumings, Amer. Jour. Sci., vol. 15, 1903, p. 26, fig. 12; p. 28, 



fig. 14; 32d Ann. Kept. Dept. Geol. Nat. Res. Indiana, 1908, pi. 35, figs. \f,lg. 

 Platystrophia lynx Hayes and Ulrich, U. S. Geol. Surv., folio, 95, illus. sheet, 



1903, figs. 21, 22. 



This variety is more globose and has a much shorter hinge line 

 than typical specimens of Platystrophia ponderosa. The shell is also 

 narrower and there are fewer plications on the lateral slopes, as the 

 number is usually five or six, becoming obsolete toward the cardinal 

 angles. 



Occurrence. — Maysville: Mount Auburn, Cincinnati, etc., Ohio; 

 Madison, etc., Indiana; Oldham County, Kentucky. 



Plesiotypes.— Cat. Nos. 65863,65864,65867, U.S.N.M. 



PLATYSTROPHIA PONDEROSA ARNHEIMENSIS, new variety. 



Plate 51, figs. 6-8. 



This variety is large, more transverse, and has broader phcations 

 on the lateral slopes than the Bellvue form of this species. 



Occurrence. — -Kichmond group Arnheim: Various localities in 

 Jefferson County, Kentucky. 



Cotypes.— Cat. Nos. 65854, 65855, 65856, U. S. N. M. 



PLATYSTROPHIA FURVALENSIS, new species. 



Plate 50, figs. 1-3. 



Dr. E. O. Ulrich collected from the Fernvale at Cape Girardeau, 

 Missouri, a large form of which the finely striated surface is the most 

 conspicuous feature. The portion next to the beak has the charac- 

 teristic coarse plications. As they extend toward the front the 

 plications of both valves bifurcate and other plications are implanted 

 in the original grooves. Towiird the front the original plications 



