236 Bulletin 39 408 



Dall also records the species from the Miocene of Santo Do- 

 mingo and Jamaica. 



Gabb's C. sapotensis, from Sapote, Costa Rica, we have not 

 seen. It is a higher and more Dosinoid shell with nearly cen- 

 tral beaks. It is possibly but a variety of this species. 



The following measurements are of Costa Rican examples: 

 I^ength 46, height 28, thickness 35 mm. 



53, 44, 16 mm (right valve) 



Gatun Stage: Gatu7i and Mt, Hope, C. Z. 

 Hill No. I, Banana River. 

 Sousi Creek ( Upper Hone creek) . 



Genus PSTARIA, Roemer 



Section LAIViELLICONCHA, Dall 



Pitaria circinata Born Plate 31 figures 3, 9 



Femes circinata Born, 1780, Test. Mus. Vind. p. 61, pi. 4, fig. 8. 



Cytherea alternata Broderip, 1835, Proc. Zool, Soc. , p. 45. 



Cytherea juncea Guppy, 1866, Quart. Journ. Geol. Soc. L,ondon, vol. 



22, p. 682, pi. 26. fig. 13. 

 Chione circinata Gabb, 1873, Tarns. Amer. Phil. Soc, vol. 15, p. 250. 

 Cytherea juncea Guppy, 1876, Quart. Journ. Geol. Soc. London, vol. 



32, p. 531- 

 Pitaria {Lamelliconc/ta) circinata Dall, 1903, Trans, Wagner Free 



Inst. Sci. , vol. 3, pt. 6, p. 1269. 

 Pitaria circinata Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci. Phila. 



vol. 63, p. 370. 

 Pitaria {Lamelliconcha) circinata Maurj-, 1917, Bull. Amer. Pal., vol. 

 5, P- 379. pl-37, fig. I- 

 The Pitaria circinata Born is a common, recent Veneroid 

 along the Caribbean coast of Panama and Costa Rica. It occurs 

 also on the west or Pacific side but in a slightly different form, 

 as the variety alternata Broderip. This variety differs from the 

 typical circinata by its larger, more convex shell and more dis- 

 tant concentric ribs. 



