305 Costa Rica Miocene— Olsson 133 



cess on the shoulder of primary varices. It is fairly abundant in 

 the Gatun beds of the Banana River. 



Gatun Stage; Hill la, Banana River. 



Genus SISTRUIVl Montfort 



Sistrum nodu!osum C. B. Adams Plate 10, figure 23 



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



P- 3. 

 Ricinida 7ioduIosa Tryon, 1880, Manual of Conch., vol. 2, p. 190, pi. 



59, fig. 275. 

 Sistrum nodulosuni 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. They 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 turbi^iella Kiener 

 and Phasianella affinis C. B. Adams. 



Uscari and Gatiai transitional beds; Zone ^ and 6, 



Red Cliff Creek. 



(O SUPER-FAMILY T^NIOGLOSSA 



Genus DiSTORTRIX- Unk 



Distortrix simiMima Sowerby 



Tritofi simillimtis 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 siniillima Guppy, 1874, Geol. Mag., p. 439. 



