339 Costa Rica Miockne— Olsson 157 



Domingo, Jamaica and Venezuela. It differs from the Gtippyana 

 by its closer and more irregular longitudinal sculpture crossed by 

 faint spirals, producing a cancellated appearance. The umbili- 

 cus is larger and more ample. 



Gatun Stage: Gaiim, C. Z. 



Water Cay, Panama. 

 Banana River, C. R. 



Genus POLINICES Montfort 

 Polinices SUbcSausa Sowerby Plate 13, figures 16, 17 



Natica siibclausa Sowerby, 1849, Quart. Journ. Geol. Soc. Ivondon, 

 vol. 6, p. 51. 



Natica subdausa Guppy, 1S66, Quart. Journ. Geol. Soc. London, vol. 



22, p. 290, pi. 18, fig. 8. 



Polinices subdausa Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci. 



Philia. , vol. 63, p. 560. 

 Polinices siibclausa Maury, 1917, Bull, Amer. Pal., vol. 5, p. 300, pi. 



23, fig- 14- 



This is a common fossil in the Miocene of Santo Domingo 

 and Jamaica. The Costa Rican shells are small, the largest 

 specimen in our collection measuring only 17 mm in altitute. 



When viewed from the dorsal side, the shell has a distinct- 

 ly NeritaASk.^ aspect, due to its low spire, close coiling and rap- 

 idly enlarging whorls and appressed sutures. The umbilicus is 

 of medium size, expanding below. The inner lip is provided 

 with a thick, heavy callus which joins above with the outer lip. 

 At the upper edge of the umbilicus, the callus carries a deep, 

 transverse groove, a most characteristic feature. 



Gatun Stage: Gatun, C. Z. 



Hill No. J, Banana River, C. R. 



Polinices StanJs3as-Meunieri Maury Plate 13, figure 7 



Polinices Stanislas-meunieri Maury, 1817, Bull. Amer. Pal., vol. 5, 

 p. 300, pi. 23, figs. 15, 16. 



