﻿36 Bulletin 21 154 



shell ; a large number of interstitial, radial lines appear (about 32 

 at the margin of the shell) and cover the larger part of the disc 

 replacing the earlier cancellation. It is an interesting fact that 

 this species began, but almost immediately abandoned, the style 

 of ornamentation which in the Miocene and Pliocene became so 

 characteristic of shells of the Bellucina type. Hinge with well 

 developed teeth ; inner margin of shell finely crenulated 



Length of shell 7 ; height 6.5 ; diameter of one valve 2 mm. 



Oak Grove, Santa Rose County, Florida. 



Cornell University collection. 



Phacoides {Bellacina) nereidideditus , n. s. 

 PI. IX, fig. 5- 



Shell nearly circular, small, resembling P. waccamawensis 

 Dall from the Pliocene of South Carolina and Florida, but 

 smaller, more alate and with an additional set of fine radiating 

 riblets which alternate with the series of broad ribs similar to 

 those of waccamawensis. Hinge strong, teeth well-developed, in- 

 terior fluted by the exterior ribs, inner margin finely and rather 

 deeply crenulated. 



Length of the single specimen found 4 ; height 4 mm. 



Oak Grove, Florida. 



Cornell University collection. 



Bornia fluctusculptiirata , n. s. 

 PI. IX, fig. 6. 

 Shell oval-trigonal, very thin and fragile, translucent, ex- 

 quisitely sculptured near either end with many radiating plir 

 cations like wavelets which are also apparent on the inside of the 

 shell. They do not extend over the center of the valves, Under 

 a lens the lines of growth are seen forming a most delicate con- 

 centric ornamentation over the entire shell on the inner as well as- 

 the outer side of the valve. Hinge very like that oi^Bomia 

 dodona Dall from Oak Grove and sculpture of the same type as 

 that of B. scintillata Dall from the Claiborne Eocene, but the 

 plications are closer in that species and extend over the ventral 



