390 SYSTEMATIC PALEONTOLOGY 



variety resembles A. staminea, its probable progenitor. The ribs vary 

 from twenty-five to thirty-one, twenty-eight or twenty-nine being quite 

 common. The teeth are fine, narrow, close set and tend to become irregu- 

 lar at the anterior and posterior ends of the dental area. 



Length, 68 mm.; height, 55 mm.; diameter, 28 mm. 



Occurrence.— St. Mary's Formation. Cove Point, Langley's Bhiff, 

 St. Mary's Eiver. 



Collections.— M'ATy\sind Geological Survey, Johns Hopkins University, 

 IT. S. National ]\Iviseum. 



Subgenus NOETIA Gray. 

 Abca (NoiiTiA) iNCiLE Say 

 Plate CVI, Figs. 3, 4. 



Area incile Say, 1824, Jour. Acad. Nat. Sci. Phila., voL iv, 1st sen, p. 139, pL x, Hg. 3. 

 Area inrile Conrad, 1832, Fossil Shells of the Tertiary, p. 16, pi. ii, lig. 1. 

 Area iHcile Courad, 1840, Fossils of the Medial Tertiary, p. 56, pi. xxix, tig. 5. 

 Area iueile Tuomey and Holmes, 1856, Pleiocene Fossils of South Carolina, p. 35, 



pi. xiv, tigs. 6, 7, 18. 

 Area ineile Emmons, 1858, Kept. N. Car. Geol. Survey, p. 2S4. 

 Anomaloeardia iueile Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 580. 

 Anadara ineile Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 6. 

 I/'oetia prolexta Conrad, 1875, Kept. N. Car. Geol. Survey, vol. i, app. A, p. lit, pi. 



iii, tig. 5 (fide Dall). 

 Area (Noetia) ineile Dall, 1898, Trans. Wagner Free Inst. Sci , vol. iii, pt. iv, p. 632. 



Description. — " Shell transversely rhomboidal, with about twenty- 

 seven ribs ; anterior hinge margin compressed and angulated. 



"Disl: prominent from the beaks to the anterior part of the base : ribs 

 with transverse granules; those anterior to the middle alternating with 

 very slender and but little prominent lines, and with a groove on each : 

 anterior margin longer to the base than the posterior end, and contracted 

 in the middle : series of teeth nearly rectilinear, entire ; interval between 

 the -teeth and the apices with a few transverse lines or wrinkles ; a single 

 oblique groove from the apex to a little Ijefore the middle, and six or 

 seven narrow ones from the teeth outwards behind the apices : heal's placed 

 very far backward : inner margin crenated : muscular impressions a little 

 elevated, posterior one short: basal margin not parallel with the hinge 

 margin." Sav, 182-1. 



