K0.1237. SYNOPSIS OF THE LUCINACEA— BALL. 825 



specific name had been chosen by Deshayes for a species of Diplodonta., 

 but as these belong in different families and were long since separated, 

 it does not seem as if the specific name need be changed, as was done by 

 d^Orbigny, who called the French fossil subradians. 



A better figure than Conrad's was given by Tuomey and Holmes, 

 but this being accessible to few students, I have refigured the species 

 from a recent specimen, 20 mm. in height, collected at Pensacola, 

 Florida. 



PHACOIDES (CALLUCINA) BERMUDENSIS, new species. 



(Plate XXXIX, tig. 5.) 



Reeve's figure of lenUcula in the Iconica fairly well represents this 

 species, though I can not be certain that the shells are identical, since 

 Reeve gives no data in regard to the hinge or interior. His name at 

 any rate is preoccupied, and it is probal)ly best to treat our specimens 

 as new. 



Shell small, discoid, suborbicular, white oi- ])rownish, equilateral; 

 beaks small and low but acute; lunule long and narrow, moderatel}' 

 impressed; escutcheon and dorsal areas absent or obsolete; sculpture 

 of close, fine, sharp, concentric lamelhv with slightly wider concen- 

 trically striated interspaces; there is no radial sculpture; hinge strong, 

 muscular impressions normal, groove for the ligament long, shallow; 

 margins of the shel! without crcnulation. Alt. 16.5, Ion. IT.O, diam. 

 7.0 nmi. 



This species somewhat resembles P. radianft^ but is entirely destitute 

 of any radial sculpture, and has a proportionately longer and narrower 

 lunule, less deeply impressed. 



PHACOIDES (PARVILUCINA) CRENELLA, new species. 



(Plate XXXIX, fig 2.) 



The small shells of this type from the Oligocene to the living fauna 

 have been called by the name of ^^Lt/ci/ia rre/iulata Conrad,'' without 

 exception, and their differences ascribed to "variability.'' Careful 

 study shows in this, as in other cases, that several distinct species 

 should ])e recognized. The original locality of Conrad's shell is the 

 Miocene of Suffolk, Virginia, where it is found abundantly. With this 

 as a standard the others have been compared. The living shell hith- 

 erto confounded with it is represented in the fossil state in the Pleis- 

 tocene of North Creek, Florida, and Simmons Bluff', South Carolina, 

 the Pliocene of North and South Carolina, and of the Caloosahatchie 

 beds, Florida. It does not appear in the Miocene. In the present 

 fauna it has a wide range. It differs from the true crenulatus as fol- 

 lows: It is thinner, more delicate, with a less heavy hinge, more tumid 

 valves, and is generally more etjuilateral and the beaks more central. 

 P. crenalatu-i has prominent, almost/ lamellose concentric sculpture, 



