26i Costa Rica Miocene — Oi^sson 



variety Giraudi Cossmann 



Oliva Giraudi Cossmann, 1913, Journ. de Conchyliologie, vol. 61, p. 

 56, pi. 5, figs. 4-8. 



A fairly common species in Cost Rica. Tj'pically the shell is 

 short; moderatly convex, a short projecting spire and concave 

 spire-whorls. 



Unusually broad forms as illustrated by figure 4 may be sep- 

 arated by the name of Giraiidi Cossmann. 

 A large typical shell measures: 

 Length 35, diameter 17 mm. 



Gatun Stage: Coll. 6, Red Cliff Creek, C. R. 



Headwaters of Middle Creek, C. R. 

 Coll. 5, Grape Poivt Creek, C. R. 



Oliva gatunensis Toula Plate 7, figure 5 



Oliva gatunensis Toula, 1909, Jahrb. der K-K. Gaol. Reicesanstaldt, 



vol. 58, p. 702, pi. 25, fig. 12. 

 Oliva retictdaris gatunensis Brown and Pilsbrj, 191 1, Proc. Acad. Nat. 



Sci. Phila. , vol. 63, p. 348. 

 Oliva gatunensis Cossmann, 1913, Jour, de Conchyliologie, vol. 61, p. 



58, pi. 5, figs. 9-12. 



A common species at Gatun. The largest specimen in our 

 collection measures 28 mm. in length but Brown and Pilsbry men- 

 tion shells of an length of 35-38 mm. Oliva gatunensis, resem- 

 bles somewhat the brevirsoira of Gabb, but has a more even con- 

 ic spire and lacks the projecting nuclear tip. The sutures are 

 appressed. Brown and Pilsbry, place this shell as a varietj^ of 

 the larger, recent Oliva reticularis Lamarck. 



Gatun Stage: Ml. Hope, C. Z. 

 Oliva sayana var. immortua Pilsbry and Brown Plate 7, figs. 6, 7 



Oliva sayana var. immortua Pilsbry and Brown, 191 7, Proc. Acad. 

 Nat. Sci. Phila., p. 33, pi. 5, fig. 6. 



The Oliva sayana Ravenel {Oliva liter ata of most Vs^riters) 



