MARYLAND GEOLOGICAL SURVEY 301 



Length, 12.5 mm.; height, 6.5 mm.; diameter, 3.5 mm. (Dall). 

 Occurrence. — St. Mary's Formation. St. Mary's River {-fide Dall). 

 Calvert Formation. Plum Point. 



Collections.— V. S. Xational Museum, Maryland Geological Survey. 



Geiuis METIS H. and A. Adams. 

 Metis biplicata Conrad. 

 Plate LXXIII, Figs. 5, 6. 



Telllna biplicata Conrad, 1834, Jour. Acad. Nat. Sci. Phila., voL vii, 1st ser., p. 152. 

 Tellina biplicata Conrad, 1840, Fossils of the Medial Tertiary, p. 36, pi. xix, fig. 4 ; 



not of Tuomey and Holmes or Emmons. 

 Metis biplicata Conrad, 1863, Proc. Acad. Nat. Sci. Phila., voL xiv, p. 573. 

 Metis biplicata Meek, 1864, Miocene Check List, Smith. Misc. Coll. (188), p. 11. 

 Metis biplicata Dall, 1900, Trans. Wagner Free Inst. Sci., vol. iii, pt. v, p. 1043. 



Description.—" Shell suboval, inequivalve, slightly ventricose, with ob- 

 scure radiating lines, and prominent filiform striaB, much elevated over 

 the folds of the posterior side ; folds two, one on each valve angular ; car- 

 dinal teeth two in the right valve, much compressed, posterior one pro- 

 foundly bifid ; one similar bifid tooth in the opposite valve ; hinge margin 

 profoundly sulcated posteriorly ; lateral teeth none." Conrad, 1834. 



Length, 60 mm. ; height, 51 mm. ; diameter, 12 mm. 



Occurrence. — St. Mary's Formation. Cove Point. Choptank For- 

 mation. Governor Eun, 2 miles south of Governor Eun, Flag Pond, 

 Cuckold Creek, St. Leonard Creek, Jones Wliarf, Sand Hill, Dover 

 Bridge, Cordova. Calvert Formation. Plum Point, White's Landing, 

 Wye Mills. 



Collections. — Maryland Geological Survey, Johns Hopkins University. 



Genus MACOMA Leach. 



Macoma lenis (Conrad). 

 Plate LXXIII, Figs. 3, 4. 



Tellina lenis Conrad, 1843, Proc. Acad. Nat. Sci. Phila., vol. i, p. 306. 



Tellina lenis Conrad, 1845, Fossils of the Medial Tertiary, p. 73, pi. xli, tig. 9. 



Tellina (Peroncederma) lenis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, 



p. 573. 

 Tellina (PeroncEoderma) lens Meek, 1864, Miocene Check List, Smith. Misc. Coll. 



(183), p. 10 (typ. er.). 

 Macoma lenis Dall, 1900, Trans. Wagner Free lust. Sci., vol. iii, pt. v, p. 1047. 



