140 BUI.I.BTIN 31 140 



Meretrix aequorea Con., PI. 44. Figs. 3-6. 



Cytherea csquorea Con., Foss. Shells &c., Aug., 1833, p. 36, (See 



Harris' Reprint, pi. 20, fig. 5. 

 C. hydii L,ea, Cont. to Geol., Dec, 1833, p. 66, pi. 2, fig. 42. 

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

 C. cequorea de Greg., in part, Mon. Faun. Eoc. Ala., 1890, p. 216. 



Conrad's orighial description. — Shell subovate, inequilateral, com- 

 pressed, with regular, distinct concentric sulci ; lunule cordiform, two car- 

 dinal teeth in the right valve, parallel and approximate. Length 1%" in- 

 ches. Breadth \% inch. 



Perhaps it is the variability of strength in the lirations that 

 characterizes this species most markedly. When young the lirse 

 may be more or less regular for a time and suggest a relation- 

 ship with viortoni, but the form of the shell is more ovate 

 and less elliptical. When seen from above (pi. 44, fig. 4) this 

 shell appears to have its sides more or less parallel for some dis- 

 tance. 



This is by all odds the most abundant species of the genus 

 at Claiborne \perovata is moderatel}' abundant, but most of the 

 other forms are rare. We have found nothing in the St. Maur- 

 ice beds corresponding to this in the Gulf states. 



Type. — Phila. Acad. 



Horizon. — Claiborne Eocene. 



Specimens figured. — Paleont. Mus. Cornell Univ. 



Locality. — Claiborne, Ala. 



Meretrix macbeani, n. sp., PI. 44. Figs. 8, ^. 



Specific characterization. — Size and general appearance shown 

 by fig. 8 ; substance of the shell rather thick ; concentric lira- 

 tions well-defined and smooth ; neither escutcheon nor lunule 

 sharply defined ; pallial sinus V-shaped ; anterior lateral tooth 

 large and strong. 



Dimensions of right valve : 21x12x5. 5 mui. 



This is but distantly related to any other Cytheroid shell 

 known to the writer from the Eocene of America. In many re- 

 spects it approaches Pitaria, s. s. as defined b}^ Dall. 



