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: 

 Length 46, height 28, thickness 35 mm. 



53, 44, 16 mm (right valve) 



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

 Hill No. I, Banana River. 

 Sousi Creek ( Upper Hone creek) . 



Genus PITARIA, Roemer 



Section LAIVIELLICONCHA, Dall 



Pitaria circijiata Born Plate 31 figures 3, 9 



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



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



Cytherea jimcea Guppy, 1866, Quart. Journ. Geol. Soc. London, 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 {Lame Hi concha') circinata Dall, 1903, Trans, Wagner Free 



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

 Pitaria circinata Ero^n and Pilsbry, 191 1, Proc. Acad. Nat. Sci. Phila. 



vol. 63, p. 370. 



Pitaria {Lamelliconcha) circinata Maur}-, 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. 



