476 ■ SYSTEMATIC PALEONTOLOGY 



PoLYMORPHiNA COMPRESSA d'Oibigny. 

 Plate CXXXIII, Fig. 1. 



Polymorphina compresm d'Orbigny, 1846, Foram. Fossiles Vienne, p. 238, pi. xii, 



flgs. 32-34. 

 Polyiiiorphina compressa Bagg, 1898, Bull. Amer. Pal., No. 10, p. 20, pi. ill, tigs. 



la, lb. 

 Polymorphina compressa Bagg, 1901, Md. Geol. Survey, Eocene, p. 24(5, pi. Ixiii, 



fig. 10. 



Description. — " Shell oblong, inequilateral, compressed, more or less 

 fusiform ; chambers numerous, arranged in two inequal series, somewhat 

 inflated; septal lines depressed; surface smooth or faintly striated; aper- 

 ture variable, usually simple, circular, coronate ; sometimes labyrinthic, 

 or porous." Brady, Parker and Jones. 



Occurrence. — Choptank Formation. Jones Wharf, 1 mile north of 

 Governor Eun. Calvert Formation. Plum Point, Chesapeake Beach. 



Collection. — Maryland Geological Survey. 



Polymorphina compressa var. striata n. var. 

 Plate CXXXIII, Fig. 2. 



Description.- — Test similar in size, amount of compression, arrange- 

 ment of chambers and in their number to P. compressa, but it differs 

 from the latter in having a number of definite costae running over every 

 chamber. There would be some doubt about the validity of this variety 

 were it not for the fact that the amount of striation is so great and so 

 entirely different from the common P. compressa. It is no doubt easy 

 to find in Brady's illustrations of the species indications of costae, but 

 when these become constant and well-defined there is good reason to re- 

 gard the forms as a variety. 



Occurrence. — Choptank Formation. Jones Wharf, Governor Run. 



Collection. — Maryland Geological Survey. 



Polymorphina elegantissima Parker and Jones. 

 Plate CXXXIII, Fig. 3. 



Polymorphina eleyantunlma Parker and Joues, 1865, Philos. Trans, of Roy. Soc, vol. 

 civ, table x, p. 438. 



Description. — Test ovoidal, anterior end acute, posterior obtusely 

 rounded; chambers four or five, elongate, arranged in an inequilateral 



