MARYLAND GEOLOGICAL SURVEY 353 



AsTARTE CFNEiFORMis Conrad. 

 Plate XCIII, Figs. 4, 5, 6. 



Astarte cuneiformis Conrad, 1840, Fossils of the Medial Tertiary, p. 43, pi. xx, fig. 9. 

 Astarte varians Conrad, 1841, Proc. Acad. Nat. Sci. Phila., vol. i, p. 39. 

 Astarte varians Conrad, 1843, Jour. Acad. Nat. Sci. Phila., vol. viii, 1st ser., p. 18*. 

 Astarte varians Conrad, 1845, Fossils of the Medial Tertiary, p. 67, pi. xxxvii, fig. 7. 

 Astarte cuneiformis Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, \i. 578. 

 Astarte cuneiformis Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 7. 

 Astarte varians Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 7. 

 Astarte cuneiformis Whitfield, 1894, Mon. sxiv, U. S. Geol. Survey, p. 53, pi. viii, 



fig. 10 only. 

 Astarte (AshtarotJta) cuneiformis Dall, 1903, Trans. Wagner Free Inst. Sci., vol. iii, 



pt. vi, p. 1494. 



Description. — " Shell trigonal, much compressed; umbo flat, with dis- 

 tant, shallow nndulations, and acnte little prominent ridges; apex very 

 acute; lunula very profound, with a sharply carinated margin; posterior 

 side produced, cuneiform, acutely rounded at the extremity; cardinal 

 teeth long and rather slender; margin crenulated.'^ Conrad, 1840. 



This shell is quite variable. The undulations near the beak may be 

 either coarse or quite fine and may extend over a good portion of the 

 surface, or they may be almost obsolete. The posterior side may be 

 much produced and acutely rounded, giving the shell a distinctly cunei- 

 form shape; or it may be only very slightly, if at all, produced, when the 

 shell becomes more compact and triangular in outline. This shortening 

 may continue until some specimens approach A. vicina in outline. The 

 inner margin may be smooth. The base may be regularly arched or 

 may be emarginate posteriorly. 



Length, 33 mm.; height, 23 mm.; diameter, 6 mm. 



Occurrence. — Calvert Formation. Chesapeake Beach, 3 miles south 

 of Chesapeake Beach, Plum Point, Truman's Wharf, Lyon's Creek. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 U. S. National Museum, Academy of Natural Sciences of Philadelphia, 

 Cornell University. 



Astarte castrana n. sp. 

 * Plate XCIII, Figs. 7, 8, 9. 



Astarte [Ashtarotha) obruta Dall, 1903, Trans. Wagner Free Inst. Sci., vol. iii, pt. vi, 

 p. 1490 (in part). 



Description. — Shell triangular, nearly equilateral, with rounded base; 



beak acute, turned slightly forward; shell flat or depressed; outer surface 

 23 



