327 Costa Rico Miocene — Olsson 155 



Genus PslATICA Scopoli 

 Natica canrena Linnaeus Plato 13, figure 9 



Natica canrena Linnaeus, 1758, Syst. Nat., ed. 10, p. 776. 



Natica canrena Gabb, i88r, Journ. Acad. Nat. Sci. Phila., voL 8, and 



series, p. 357. 

 Natica canrena Brown and Pilsbry, 19 r 2, Proc. Acad. Nat. Sci. Phila., 



p. 508, 

 Natica canrena Maury, 1917, Bull. Amer. Pal., vol. 5, p. 298, pi. 23, 



fig. 10. 



This is a recent species but also common as fossil in the Mi- 

 ocene of the West Indies and the States. It is a warm water 

 species so that in the Chesapeake Miocene of the eastern United 

 States, it is found only in the warm, upper or Duplin stage. We 

 collected several specimens at Gatun but none at Costa Rica. 

 Gabb however has recorded it as abundant from the Limon Pen- 

 insula but whether his specimens were obtained ; from the Mio- 

 cene or Pliocene is not known. 



The species is distinguished by its strong, tangential, su- 

 tural plicse, but the main surface of the whorl is otherwise 

 smooth. 



Gatun Stage: Gatun, C. Z. 



Natica Youngi Maury, var., COCieana, n. var. Plate 13, figure 8 



cf, Natica Yotmgi Maury, 1917, Bull. Amer. Pal., vol. 5, p. 299, pi. 

 23, figs. II, 12. 



Shell subglobular with 5 rounded and convex whorls; sur- 

 face smooth but with irregular, coarse growth lines about the su- 

 tures; the surface is also faintly straited with weak spiral lines 

 as may be seen on several otherwise smooth Naticas; aperture 

 semilunar with a narrow callus on the inner lip, slightly thicker 

 about opposite the middle of the umbilicus; umbilicus small, 

 with the umbilical callus small and but poorly developed. 



I^ength or height 25, diameter 34 mm. 



