564 



NORTH AMERICAN INDEX FOSSILS. 



561. M. eufaulensis (Conrad). Cretacic. 

 Nearly rotund. Concentric striae fine and especially conspicuous 



and regular for half the distance down from the beak. 



Ripleyan of New Jersey (Marshalltown-Navesink), Alabama. 



562. M. veta (Whitfield). (Caryatis veta.) Cretacic. 

 Length less than 1 inch. Pallial line faint and with a deep and 



Fig. 773. Meretrix tippana. (N. J. Pal., I.) 



narrowly rounded sinus. External surface rarely well preserved, 

 marked with fine concentric lines. 



Jerseyan of New Jersey (Hornerstown-Manasquan). 



563. M. ripleyana Gabb. (Fig. 774.) 



Cretacic and lower Eocenic. 

 Shell nearly smooth around the umbo but marked with concen- 

 tric lines from the middle downwards. 



Eocenic (Midway) of Georgia and Texas. Cre- 

 tacic (Ripley) of Tennessee. 



564. M. subimpressa Conrad. (Fig. 775, d-f.) 



Eocenic. 



Produced posteriorly so that length considerably 

 exceeds breadth. 



Maryland (Nanjemoy), Alabama (Lignitic). 



Fig. 774. 

 Meretrix ripley 

 ana. (After 

 Harris.) 



565. M. uvasana Conrad. Eocenic. 



Over 2 inches long by 1.75 inches high. Beaks nearly ante- 

 rior. Surface marked with concentric ridges separated by wider 

 spaces which are either plain or striated. 



Tejon : California, Oregon. 



$66a. M. ovata var. pyga Conrad. (Fig. 775, a, b.) Eocenic. 

 Large, thick, ventricose, oval. 

 Aquia : Maryland. 



