MARYLAND GEOLOGICAL SURVEY 277 



rior portion not or but slightly expanded; posterior not or bnt slightly 

 contracted and prodnced; surface with irregular, concentric nndula- 

 tions, more or less strongly marked and sometimes lamellar. 



It differs from P. goldfussii Wagner in being more equilateral, less 

 expanded anteriorly and less contracted and produced posteriorly. 



Length, 90 mm.; height, 51 mm.; diameter, 8 mm. 



Occurrence. — Choptaxk Formatiox. Governor Eun (lower bed). 

 Calvert Formation. Plum Point, Lyon's Creek, White's Landing, 

 Wye Mills, Fairhaven, Xcav Town (?). 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum. 



Panopea goldfussii AVagner. 

 Plate LXVI, Fig. 1. 



Panopea Goldfussii Wagner, 1839, Jour. Acad. Nat. Sci. Phila., vol. viii, 1st ser., 



p. 5a, pL i, fig. 3. Probably published privately in 1838. 

 Panopcea porrecta Conrad, 1843, Fossils of the Medial Tertiary, p. 71, pi. xli, fig. 2. 

 Glycimeris Goldfussii Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 571. 

 Panopcea Goldfussii Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 12. 

 Panopcea porvecta Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 12. 

 Panopea Goldfussii Dall, 1898, Trans. Wagner Free Inst. Sci., vol. iii, pt. iv. p. 829. 



Description. — " Shell oblong, subovate, ventricose; disks with con- 

 centric, unequal, shallow grooves; lines of growth coarse and prominent; 

 anterior extremity slightly gaping; anterior margin rounded, anterior 

 dorsal margin elevated; posterior side narrowed, somewhat produced, 

 not reflected; posterior dorsal margin nearly rectilinear; cardinal teeth 

 obliquely compressed, united at base to the nympha, short and not 

 very prominent." Wagner, 1839. 



Length, 117 mm.; height, 58 mm.; diameter, 21 mm. 



Occurrence. — St. Mary's Formation. Cove Point, St. Mary's Eiver. 

 Choptank Formation. Governor Eun (lower bed), Jones Wharf, Paw- 

 paw Point. Calvert Formation. Plum Point, Wye Mills, New 

 Town(?). 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum. 



