336 SYSTEMATIC PALEONTOLOGY 



Shell nearly hemispherical, length slightly greater than height; car- 

 dinal teeth small, projecting, in right valve three, in left valve two, 

 ligament area narrow; muscular impressions sometimes indistinct; exter- 

 nal surface nearly smooth. Eare and very difficult to obtain entire. 



Length, 34 mm.; height, 32 mm.; diameter, 14 mm. 



Occurrence. — Choptank Formation. Governor Run, Flag Pond, 

 Jones Wharf. Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



Family LUCINID/E. 



Genus PHACOIDES Blainville. 

 Subgenus PSEUDOMILTHA Fischer. 



Phacoides (Pseudomiltha) foremani (Conrad). 

 Plate XC, Figs. 1, 2. 



Lucina Foremani Conrad, 1841, Proc. Acad. Nat. Sci. Pbila., vol. i, p. 29. 

 Lucina Foremani Conrad, 1842, Jour. Acad. Nat. Sci. Phila., vol. viii, 1st ser., p. 184. 

 Lucina Foremani Conrad, 1845, Fossils of the Medial Tertiary, p. 71, pi. xl, fljj. 4. 

 Lucina Foremani Conrad, 18(53, Proc. Acad. Nut. Sci. Phila., vol. xiv, p. 577. 

 Lucina foremani Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 8. 

 Phacoides (Pseudomiltha) Foremani Dall, 1903, Trans. Wagner Free Inst. Sci., vol. 

 iii, pt. vi, p. 1378. 



Description. — " Orbicular, ventricose, moderately thick; surface with 

 irregular shallow grooves, and rather distant prominent strise, with 

 intermediate, fine, concentric lines; posterior margin subtruncated obli- 

 quely outwards; beaks prominent, not central; hinge edentulous. 

 Length, 1| inch." Conrad, 1841. 



It may be distinguished from P. anodonta by being smaller and much 

 more convex; as found in Maryland, the interior, prismatic portion of 

 the shell is often badly decayed, while the exterior portion is usually 

 well preserved; it is at times quite thick. 



Length, 35.5 mm.; height, 34 mm.; diameter, 8.5 mm. 



Occurrence. — Choptank Formation. Governor Run. Calvert For- 

 mation. Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



