382 Pro'JccJ.ings of the Ohio State Acadciuy of Science. 



1894. Dielasiiia lurgida. Hall and Clarke, Int. to Study of Brach., pt 



■1, ])!. 53, figs. 10-12. 

 Chester limestone : Spencer County, Indiana. 

 St. Louis group : Washington County, Indiana. 



1895. Dielasina turglda. Hall and Clarke, Pal. N. Y., Vol. VIII, pt. 2, 



pi. 81, figs. 1-8. 

 Chester limestone: Spencer County, Indiana. 

 St. Louis group : Washington County, Indiana. 

 18!I5. Terebratiila turcjida. Whitfield, Geol. Snrv. Ohio, Vol. VII, p. 

 473, pi. 9, figs. 21, 22. 

 Maxville limestone: Maxville and Newtonville, Ohio. 

 190(3. Dielasina furgiditm. Beede, Ind. Dept. Geol. Nat. Res., 30th Ann. 

 Rep. p. 1309, pi, 22, figs. 53-58; pi. 19, figs. 5-5a. 

 Salem limestone: Indiana, Illinois and Missouri. 

 1909. Dielasina turgidiuin. Grabau and Shimer, N. A. Index Foss., p. 

 302, fig. 376 d-f. 

 Warsaw and St. Louis : Ohio, Kentucky, Indiana, Illinois, Mis- 

 souri, Iowa. 



Description. — Shell small, egg-shape in general outline, 

 elongate, nearly as thick as broad with anterior end truncated 

 and slightly emarginated. 



Fig. 12. — Dielasina turgida. 



a and b. — Dorsal and profile views of the same specimen. (After 

 Whitfield.) 



Pedicle valve convex, with a rather deep median sinus in 

 the anterior half. Beak incurved, obliquely truncate, with a 

 round foramen. 



Brachial valve convex with two small grooves in the anterior 

 portion of the valve of some specimens. 



Shell structin^e finely pimctate, and surface ornamented 

 with faint lines of growth. 



Length y-ii mm. ; width 5-10 mm. 



