MARYLAND GEOLOGICAL SURVEY 337 



Phacoides (Pseudomiltha) anodonta (Say). 

 Plate XC, Figs. 3, 4. 



Lucina cmodonta Say, 1824, Jour. Acad. Nat. Sci. Phila., vol. iv, p. 146, pi. s, fig. 9. 

 Lucina anodonta Conrad, 1840, Fossils of the Medial Tertiary, p. 39, pi. xx, fio-. 4. 

 Lucina anodonta Tuomey and Holmes, 18.56, Pleiocene Fossils of South Carolina, 



p. 55, pi. xviii, fig. 3. 

 Lucina Americana Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 577. 

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

 Phacoides [Fxeudomiltha) anodonta Dall, 1903, Trans. Wagner Free Inst. Sci. vol. iii 



pt. vi, p. 1378. 



Description. — " Orbicular, slightly transverse, compressed: teeth obso- 

 lete. 



"Shell with elevated wrinkles; orbicular, a little transverse, with a 

 very slight impressed longitudinal line on the anterior margin; anterior 

 and posterior ends equally curved; apices not prominent beyond the 

 general curve of the shell, with a very short, deep emargination behind 

 them; teeth obsolete; both the cardinal and lateral ones are generally 

 altogether wanting; lunule .short, cordate, profound. . . . 



" The impressed line on the anterior part of the shell is hardly visible 

 in many specimens, and is sometimes only a very slight undulation, not 

 observable but on close inspection. . . ." Say, 1824. 



Distinguished readily by its being flat, toothless and usually thick, 

 with distinct pallial line and muscle impressions. 



Length of very large specimen, 69 mm.; height, 65 mm.; diameter, 

 10 mm. 



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

 Choptank Formation. Governor Eun, 2 miles south of Governor Run, 

 Flag Pond, Jones Wharf, Turner, Dover Bridge, Peach Blossom Creek. 

 Calvert Formation. Chesapeake Beach, 3 miles south of Chesapeake 

 Beach, Plum Point. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



Subgenus HERE Gabb. 

 Section CAVILUCINA Fischer. 



Phacoides (Here) trisulcatus (Conrad). 

 Plate XC, Figs. 7, 8, 9. 



Lucina trisulcata Conrad, 1841, Amer. Jour. Sci., vol. xli, p. 346. 



Lucina trisulcata Conrad, 1845, Fossils of the Medial Tertiary, p 71 pi xl fio- 13 



