35 St. Maurice and Ci^aiborne Pelecypoda 



collection are not perfect enough for further determinations. 

 Type. — Lea Coll., No. 5074, Phila. Acad. 



Crenella latifrons Conrad, PI. 17. Figs. 14, 15, 16. 



CrcncIIa latifronsQ.o\\.,]r.V\\\\A. Acad. Nat. Sci., vol. IV, i860, p. 



296. 

 C? latifrons Con., Amer. Conch., vol. i, 1855, p. 11. 



Conrad's original description. — Obliquely sub-oval, inflated, thin, 

 highly pearlaceous ; anterior side produced or alated above ; strire very 

 closely arranged, elegant and minute, cancellate anteriorly. 



Locality. — Alabama. Dr. Showalter. 



Otto Meyer described {Bericht itb. d. Scnckcnbergischc nj. 

 Gesel. in Frankf^irt a. M., 1887, p. 10 sond.-Ab.) a Modiola teuuis 

 and figured the same as fig. 7 and pi. 2 of his report, from the 

 Jackson Eocene. This, Dall maintains is the same as Conrad's 

 Crenella latifrons. (See Trans. Wag., Ill, p. 798.) This is 

 quite possibly true. But Meyer .strangeh" makes no reference to 

 the radiating lines .so clearly defined in the Claibornian species. 

 We have several fragmentary specimens before us mo.stly from 

 the U. S. Nat. Mus. Claiborne .sand material. Some we herewith 

 figure. 



. Perhaps the most noteworthy feature of the species is the 

 broadly out-folding anterior margin of the shell. 



The radiating striae are very much finer than in margaritacca 

 and do not show on the margins. 



Type. — Claiborne sands, Phila. Acad. 



Crenella margaritacea Conrad, PI. 17. Figs. 17-20. 



Stalagminni inargaritaceuin Con., Foss. Sh. Tert. Fonn, Oct., 1833, 



P- 39- 

 Jfyoparo costata Lea, Cont. to Geol., Dec. '33, p. 74, p. 74, pi. 2, fig. 51. 

 Stalaginiuvi margaritaceuin Con., Jour. Conch., 1865, p. 10. 

 Crenella costata de Greg., Faun. Hoc. Ala., 1S90, p. 185, pi. 22, figs. 



8-14. 

 Crenella margaritacea Dall, Trans. Wag., Ill, '98, p. 803. 

 Conrad's original description. — Shell very small, ob-ovate, convex, 

 with distinct, ra^diating stride ; beaks prominent and curved forward ; lunule 

 short, cordate, slightly impres,sed ; inner margin minutely crenulated. 



Specimens of this minute vah-e are not rare at Claiborne, 

 l>ut we have .seen it from but one other locality — Lee Co., Tex., 



