534 Systematic Paleoxtology 



Collections. — Maryland Geological Survey, U. S. National Museum. 



Outside Distribution. — Black Creel- Formation. Exogyra ponderosa 

 zone of North and South Carolina. Eutaw Formation (Tombighee sand). 

 Exogyra ponderosa zone, Mortoniceras subzone, Georgia. Exogyra pon- 

 derosa zone, Chattahoochee River. Alabama, and (?) Booneville, Mis- 

 sissippi. 



CUCULL^A ANTROSA Morton 



Cucullaa antrosa Morton, 1834, Synop. Org. Rem. Cret. Group, U. S., p. 65, 



pi. xiii, fig. 6. 

 Cucullaa antrosa Meek, 1864, Check List Invert. Fossils, N. A., Cret. and 



.lur., p. 8. 

 Idonearca antrosa Conrad, 1868, Cook's Geol. of New Jersey, p. 725. 

 Idonearca antrosa Conrad, 1872, Proc. Acad. Nat. Sci., Phila., p. 54. 

 Idonearca antrosa Gabb. 1876, Proc. Acad. Nat. Sci., Phila., p. 315. 

 Idonearca antrosa Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, p. 96, 



pi. xiii, figs. 6-11. 

 Cuculhva antrosa Johnson, 1905, Proc. Acad. Nat. Sci., Phila., p. 8. 

 Cucullaa antrosa Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, p. 



391, pi. xxxii, figs. 7-9. 



Description. — " An extremely ventricose cast, marked with numerous 

 longitudinal stride; beaks prominent and incurved." — Morton, 1836. 



Type Locality. — New Jersey. 



Shell known only from cast. Outline of cast subequilateral and very 

 globose, the maximum diameter slightly above the median line; anterior 

 lateral margin squarely truncate medially, rounding abruptly into the 

 dorsal and broadly into the ventral margin ; posterior lateral margin 

 slightly oblique; basal margin feebly arcuate; umbones inflated, ortho- 

 gyrate, proximate, placed a little in front of the median line; hinge char- 

 acters not known ; buttress scar profound, extending from the pallia] line 

 to the umbonal region where it gradually evanesces. 



Cucullaa antrosa Morton is well characterized by its globose outline 

 and very prominent inflated medial umbones. It far exceeds all of the 

 co-existenl species in degree of convexity. 



Occurrence. — Moxmouth Formation. Bohemia Mills. Cecil County. 



