138 BuivI^ETlN 31 138 



pearing in some elongate forms singularly like sylvcerupis, but 

 without the long anterior, and concave lunular margin of that 

 species, therefore approaching \\\ow\Xva(t subimpressa Con., but 

 with deeper valves and passing gradually through shorter forms 

 (fig. 10 and var. siibvitrea de Greg., fig. 11) into ty ^\q:?\ Per ovata . 



7)'/t'.r.— Paleont. Mus. C. U. 



Horizo7i. — St. Maurice and Claiborne Eocene. 



Specimens figured. — Paleont. Mus., Cornell Univ. 



Localities. — Lisbon, base of Claiborne Bluff, Ala. ; 3 and 6 

 miles W. N. W. of Orangeburg, S. C. 



Meretrix perovata Con., PI. 43. Figs. 11, 12 a, 13. 



Cytherea perovata Con., Foss. Sh. Tert. Form., Aug., 1833, p. 37, 

 Cytherea comis Lea, Cont. to Geol., Dec, 1833, p. 66, pi. 2, fig. 41. 

 Dione perovata Con., Jr. Amer. Conch., vol, i, 1865, p. 6. 

 Cytherea cequorea vars. comis and cotnifidiUa de Greg., Mon. F'aun. 

 Eoc. Ala., 1890, p. 217, pi. 34, fig. I, 2, 3, 4, 6, 7, 



Conrad's original description. — Shell cuneiform, ovate, convex, smooth 

 and polished, slightly sulcated on the inferior half of the valves ; posterior 

 side slightly compressed and cuneate ; umbo tumid, beaks almost anterior ; 

 two anterior cardinal teeth in the right valve, approximate and parallel ; 

 lunula cordate and defined by a simple impressed line. Length i^ inches. 

 Breadth i inch. Claiborne. Cab. Acad., N. S. 



That this is an extremely variable species we are read}^ to ad- 

 mit, ranging from the tumid, typical forms with but the peri- 

 pheral beginnings of coarse liration, through more extensively 

 marked, somewhat less inflated specimens called var. aldrichi 

 (pi. 24, figs. I, 2) to the large flat nwrtoni ^A\.\\. its strong even 

 concentric lirations. In the Jackson the siibvitrea var. is repre- 

 sented by ayincxa Con. and the aldrichi var. by pearlensis Har. 

 But, that it is a variety of cBqiiorea we seriously question. Greg- 

 orio's <:<?;«mfl'z//« seems to include both, mortoni and our variety 

 aldrichi. 



For a discus.sion of var. aldrichi Har., see these Bulletins, 

 vol. I. 1895, p. 48, pi. I, fig. I. 



Type. — {Oi perovata, Phila. Acad., of var. aldrichi, Texas 



