MARYLAND GEOLOGICAL SURVEY 689 



Conrad. The latter is, however, less produced posteriorly and its dorsal 

 margin is more gibbous. 



Though less conspicuous a factor than C. major n. sp., it is almost as 

 abundant in number of individuals in the Monmouth of Prince George's 

 County. 



Occurrence. MONMOUTH FORMATION. Brightseat, Brooks estate near 

 Seat Pleasant, 1 mile west of Friendly, Fort Washington, Prince George's 

 County. 



Collections. Maryland Geological Survey, Philadelphia Academy of 

 Natural Sciences, TJ. S. National Museum. 



Outside Distribution. Black Cr&ek Formation. North and South 

 Carolina. Eutaw Formation. Exogyra ponderosa zone (basal), Eussell 

 County, Alabama. (Tombigbee sand member) Exogyra ponderosa zone, 

 Mortoniceras subzone, Eussell County, Alabama. Ripley Formation. 

 Exogyra ponderosa zone, Georgia; Eussell County, Alabama. Exogyra 

 costata zone, Georgia ; Eufaula, Alabama ; Union and Tippah counties, 

 Mississippi. Extreme top of zone, Pataula Creek, Georgia ; Chattahoochee 

 Biver, Alabama. 



CYPRIMERIA MAJOR n. sp. 



Plate XL, Figs. 11, 12; Plate XLI, Figs. 1-4; Plate XLII, Fig. 1; 

 Plate XLIII, Fig. 1 



Description. Shell porcellanous, very heavy and crumbly, and far 

 exceeding all co-existent members of the genus in maximum dimensions ; 

 altitude attained fully 95 mm., and latitude 100 mm. ; convexity moder- 

 ately high for the genus, the maximum diameter falling a little above the 

 median horizontal ; outline ovate or subtrigonal ; umbones evenly but not 

 greatly inflated, the apices rounded, acute, prosogyrate, anterior; lunule 

 not differentiated ; escutcheon suggested by the bevelling of the inner sur- 

 face of the dorsal margin ; anterior dorsal slope steeper, more uniform and 

 less produced than the posterior ; general direction of the dorsal margins 

 at right angles to one another but swing to a flexure in the posterior slope 

 between one-third and one-fourth of the distance from the umbones to the 



