62 Bulletin 9 ' 254 



less development of the umbones. " 



The nomenclature of the lower Eocene Meretrices is still in 

 an extremely unsettled state. Specimens of this species from 

 Woods bluff are extremely abundant, well preserved and typ- 

 ical in form. Those from the mouth of Bashi creek and Ozark 

 are still quite typical though somewhat smaller than at Woods 

 bluff and sometimes tending to be a little more triangular in 

 outline. The same remark applies to those from four miles 

 above Hamilton bluff on the Alabama. 



Variety greggi n. var. PI. 13^ figs, i, 2. 



Syn. Meretrix niittalliopsis Har., Proc. Acad. Nat. Sci. Phila., 1896, 

 pL 22, figs. I, 2. Erroneously written M. niortoniopsis 1. c, 

 P- 477- 



Descending in the geologic scale to Bell's and Gregg's land- 

 ings and Lower Peach Tree, somewhat wider variations are 

 met with. The forms more rotund posteriorly, probably fe- 

 males (pi. 13, fig. i) have a close resemblance to 7iuttalliopsis, 

 while the specimens more pointed posteriorly, probably males, 

 (pi. 13, fig. 2) would not at first sight be placed under this 

 species. 



Variety fulva n. var. PI. 12, figs. 8-IO. 



At Yellow bluff on the Alabama, and at Ft. Gaines, Ga., a 

 variety occurs still farther separated from the typical form. 

 Here also two mutations are observable, probably owing to sex, 

 one rounded posteriorly, the other more or less pointed. Fig. 

 ID shows the blunt form, young, fig. 9 the pointed form, young, 

 fig. 8 an adult. This form is unusually developed anteriorly, 

 and has a tendency to become inflated or bulged up along the 

 umbonal ridge. The reason for not giving a new specific name 

 to this marked variety is, that some of its phases are indis- 

 tinguishable from certain forms of greggi, and the latter is 

 certainly but a variety of niittalliopsis. The intimate relation- 

 ship, or perhaps specific identity of this species with Meretrix 

 riplyana Gabb, will doubtless be satisfactorily proven. Like- 

 wise its identity with M. ovata Rogers, and other Virginian 

 forms will probably be shown. 



Type specimens ^gured. — Paleontological Museum, Cornell 

 University. 



