MARYLAND GEOLOGICAL SURVEY 313 



Callocardia (Agriopoma) prunensis n. sp. 

 Plate LXXV, Figs. 4, 5, 6. 



Description. — Shell small, oval, convex or vaulted; beak elevated, pro- 

 jecting; anterior side nearly straight; anterior end regularly rounded; 

 posterior side gently convex; posterior end somewhat more acutely 

 rounded than the anterior end ; base regularly arched ; teeth normal ; car- 

 dinal area rather broad ; ligament impressions and pallial sinus distinct ; 

 exterior polished, with a few shallow, concentric growth striae here and 

 there. 



It differs from C. elevata H. C. Lea in its shape, in being polished and 

 in lacking the gentle, irregular undulations or slight ridges characteristic 

 of the elevata. 



Occurrence. — Calvert Formation. Plum Point. 



Collection. — Maryland Geological Survey. 



Callocardia (Agriopoma) sayana (Conrad). 

 Plate LXXIII, Figs. 13a, 14. 



Cijthena concexa Say, 1824, Jour. Acad. Nat. Sci. Phila., vol. iv, 1st ser., p. 149, 



pi. xii, fig. 3 ; not of Brogniart, ISll. 

 Cytherea Sayana Conrad, 1833, Amer. Jour. Sci., vol. xxiii, p. 345. 

 Cytherea Sayana Conrad, 1838, Fossils of the Medial Tertiary, p. 13, pi. vii, fig. 3. 

 Cytherea convexa Gould, 1841, Invert. Mass., p. 84, fig. 49. 

 Venus Sayana d'Orbigny, 1853, Prod. Pal. Strat., vol. iii, p. 108, No. 2011. 

 Venus Sayana Tuomey and Holmes, 1856, Pleiocene Fossils of South Carolina, p. S3, 



pi. xxi, fig. 9. 

 Cytherea Sayana Emmons, 1858, Kept. N. Car. Geol. Survey, p. 294, fig. 221. 

 Bione Sayana Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 575. 

 Dione Sayana Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 10. 

 Cytherea convexa Gould (Binney's), 1870, Invert. Mass., p. 131, tig. 444. 

 Dione Sayana Whitfield, 1894, Men. xxiv, U. S. Geol. Survey, p. 75, pi. xii, tig. 1. 

 Callocardia {Agriopoma) sayana Dall, 1903, Trans. Wagner Free Inst. Sci., vol. iii, 



pt. vi, p. 1261, pL Ivi, fig. 16. 



Description. — "Shell subcordate; elevated convex, concentrically 

 wrinkled, inequilateral; posterior tooth and fosset not striated; edge not 

 crenated; umbo rather prominent; lunule dilated, cordate, marked by a 

 simple line." Say, 1824. 



As compared with C. suhnasuta, the only species with which it is apt to 

 be confused, the sayana, has a thicker shell, is more highly convex, has a 



