MARYLAND GEOLOGICAL SURVEY 249 



vex ; surface covered with irregular, closely-set, beaded, vermicular riblets ; 

 subseptal umbilicus large and flaring. 



Height, 5 mm. ; length, 11 mm. ; width, 9 mm. 



Occurrence. — Choptank Formation. Greensboro. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



Genus CREPIDULA Lamarck. 

 Crepidula fornigata (Linne). 

 Plate LIX, Figs. 4a, 4b. 



Patella fornicata Linne, 175S, Syst. Nat., ed. x, p. 781. 



Crepidula fornicata Lamarck, 1801, Anim. sans Vert., vol. vii, p. 6-11. 



Crepidula fornicata ? var. Say, 1822, Jour. Acad. Nat. Sci. Phila., vol. ii, 1st ser., 

 p. 325. 



Crepidula densata Conrad, 18-1:3, Proc. Acad. Nat. Sci. Phila., vol. i, p. 311. 



Crepidula ponderom H. C. Lea, 1843, New Fossil Shells from the Tertiary of Vir- 

 ginia, Abst., p. 6. 



Crepidula corrutcopice H. C. Lea, 1843, New Fossil Shells from the Tertiary of Vir- 

 ginia, Abst., p. 6. 



Crepidula cymbceforrnis Conrad, 1844, Proc. Acad. Nat. Sci. Phila., vol. ii, p. 173. 



Calyptriea (Crepidula) ponderosa H. C. Lea, 1845, Trans. Amer. Philos. Soc, vol. 

 ix, p. 249, pi. XXXV, fig. 40. 



Calyptrcea (Crepidula) cornucopice II. C. Lea, 1845, Trans. Amer. Philos. Soc, vol. 

 ix, p. 250, pi. XXXV, tig. 41. 



Crypta fornicata Tuomey and Holmes, 1857, Pleiocene Fossils of South Carolina, 

 p. 110, pi. XXV, fig. 9. 



Crepidula foriiicata Emmons, 1858, Kept. N. Car. Geol. Survey, p. 276, fig. 194. 



Crypta ci/mbceformis Conrad, 1861, Fossils of the Medial Tertiary, No. 4, p. 81, pi. 

 xlv, fig. 7. 



Crypta densata Conrad, 1861, Fossils of the Medial Tertiary, No. 4, p. 81, pi. xlv, 

 fig. 9. 



Crypta fornicata Conrad, 1861, Fossils of the Medial Tertiary, No. 4, p. 81, pi. xlv, 

 fig. 10. 



Crypta cornucopia Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 569. 



Crypta cijmhieformis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 569. 



Crypta densata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 569. 



Crypta fornicata ? Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. .569. 



Crypta cornucopia Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 15. 



Crypta cymbiformis Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 15. 



Crypta demata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 15. 



Crypta fornicata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 15. 



Crepidula rostrata Conrad, 1870, Amer. Jour. Conch., vol. vi, p. 77. 



Crepidula virginica Conrad, 1870, Amer. Jour. Conch., vol. vi, p. 78. 



Crepidula recurvirostra Conrad, 1870, Amer. Jour. Conch., vol. vi, p. 78. 



Crepidula fornicata Meyer, 1888, Proc. Acad. Nat. Sci. Phila., vol. xl, p. 170. 



Crepidula fornicata Dall, 1892, Trans. Wagner Free Inst. Sci., vol. iii, pt. ii, p. 356. 



Crepidula fornicata ? Whitfield, 1894, Mon. xxiv, U. S. Geol. Survey, p. 123. 



