I40 BuivLETlN 31 140 



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



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



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

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

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

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



Com-ad's original description. — Shell subovate, inequilateral, com- 

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

 dinal teeth in the right valve, parallel and approximate. IvCngth i^ in- 

 ches. Breadth 1% inch. 



Perhaps it is the variability of strength in the Hrations 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 mortoni, 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 moderately 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. 



Speci}ne7is figured. — Paleont. Mus. Cornell Univ. 

 N Locality. — Claiborne, Ala. 



Meretrix macbeani, n. sp., PI. 44. Figs. 8, 9. 



Specific characterization. — Size and general appearance shown 

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

 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 mm. 



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 by Dall. 



