68 Bulletin 4 183 



stones. Some of these were figured. They are so variable in 

 form, however, that it has seemed and still seems unwise to 

 attempt st>ecific descriptions of them. In a future work it is 

 intended to go over all Eocene genera systematically and the 

 then accessible material will doubtless be far more satisfactory 

 than that which we now possess. 



The commonest Meretrix in the Alabama Midway is nearly 

 circular in outline below, but with a very strong umbonal region, 

 marked evenly on its exterior with concentric rugae. This is a 

 very common form in the horizon of beds 18 and 19 in Wilcox 

 Co., and in the R. R. cut lYz miles N. E. of Clayton, Barbour 

 Co. It is also found in the limestone of Limestone Co., Texas. 



TELLINA. 



Tellina, ._y£xjOi_ii-^_>_A../aj..^ ' PI. 6, fig. 8. 



The specimen shown by the figure was found with many others 

 in bed y, at Hannah's, p. 18. Since all are mere casts it seems 

 unwise to give them a new specific name. 



Another species more like Aldrich's T. triangularis was found 

 along the Chattahoochee. Doubtless more perfect specimens of 

 both species will be found in the course of a few years. 



CORBULA. 



Corbula subcompressa, PI. 6, fig. 9. 



Syn. C. subcompressa Gabb, Jr. Ac. Nat. Sci., Phila. , vol. iv, 

 i860, p. 394, pi. 68, fig. 24, 



Gabb' s original description. — " Subquadrate, beaks nearly cen- 

 tral; umbones large, umbonal ridge angular, umbonal slope 

 abrupt, anterior margin regularly rounded, posterior slightly 

 sinuous, posterior subbiangular; hinge very small. 



' ' Di77iensions . — Length .14 in., width .22 in. 



''Locality. — Two miles E. of Middleton, Hardeman Co., Tenn. 



' ' This species resembles closely C. compressa Lea, from the 

 Eocene of Ala. , although it is undoubtedly distinct. 



Both of Gabb's types are left valves. The specimen he fig- 

 ured is probably not the same one shown on pi. 6, fig. 9, but it 

 has essentially the same form. In just the right light a trace of 

 a radiating sinus is observable anterior to the umbones and an- 

 other just anterior to the umbonal ridge. 



Type specimens. — R. R. cut, 2 mi. E. of Middleton, Tenn,, now 

 in Dr. Safford's collection, Vanderbilt University, Tenn. 



