305 



Costa Rica Miocene —Olsson 



133 



cess on the shoulder of primary varices. It is fairl}^ abundant in 

 the Gatun beds of the Banana River. 



Gatun Stage; Hill la, Bana7ia River. 



Genus SS STRUTS Montfort 



Sistrum nodufosum C. B. Adams Plate 10, figure 23 



Purpura nodulosa C. B. Adams, 1845 Proc. Bost. Soc. Nat. History, 

 P- 3. 



Ricinula nodulosa Tryon, 18S0, Manual of Conch., vol. 2, p. 190, pi. 

 59, fig. 275. 



Sistrum nodulosuin Dall and Simpson, 1901, Bull. U. S. Fish. Com., 

 vol. I, p. 411. 



Worn specimens of the species occur in the transitional beds 

 of Red Cliff Creek. Thev cannot be separated from recent ex- 

 amples from the present coast. It is very common as a recent 

 species on the rocks and reefs along the northern Costa Rican 

 and Panama coast, where it occurs about high-water level, asso- 

 ciated with the equally as abundant Engina turbinella Kiener 

 and Phasianella affinis C. B. Adams. 



Uscari and Gatun transitional beds; Zone 5 and 6, 



Red Cliff Creek. 



(C) SUPER-FAMILY T^NIOGLOSSA 



Genus DSSTORTRIX Link 



Distortrix simillima Sowerby 



Triton simillimus Sowerby, 1849, Quart. Journ, Geol. Soc. London, 

 vol. 6, p. 48. 



Persona simillima Guppy, 1866, Quart. Journ. Geol. Soc. London, vol. 



22, p. 288, pi. 17, fig. 13. 

 Distortia simillimus Gabb, 1873, Trans. Amer. Phil. Soc, vol. 15, p. 



212. 



Persona simillima Guppy, 1874, Geol. Mag., p. 439. 



