389 



Costa Rica Miocene— Olsson 



117 



with 10 spirals on the penultimate wborl, about 26 on the last; 

 aperture long, with a thickened outer lip, internally lirated in 

 unison with the external spiral cords; inner lip smooth with a 

 long, bent, beak-like canal. 



Length 27, diameter 9.50, last whorl 19, aperture 14, 

 spire 13 mm. 



Several specimens from the coral limestones of Port Limon. 

 The}^ are most closely related to Harrisi, in their heavy shell, 

 coarse sculpture, and thickened outer lip. They differ in being 

 more slender, a longer aperture and in minor details of their 

 sculpture. 



Gatun Stage: Port Lmton, 



Genus PHOS Montford 



Phos gatunensis Toula Plate 9, figures 4, 5 



Phos gatunensis Toula, 1909, Jahrb. der K-K Geol. Reichsanstalt, Wein 



vol. 38, p. 701, pi. 28, fig 6; pi. 25, fig. II. 

 Phos gatunensis Brown and Pilsbry, 1911, Proc. Acad. Nat. Sci. Phila. 



vol. 63, p. 349, pi. 25, figs. I, 2. 



The Phos gatunensis is possibl3^ the most common fossil in 

 the Gatun beds of the Canal Zone and the adjacent sedimentary 

 areas in the Province of Colon, but it still remains to be collected 

 outside of this, its type area. 



The shell is typically rather slender, with a sub -reticulate 

 sculpture formed by the intersection of its numerous, straight 

 longitudinal ribs, and the nearly equal, regular, strap-like, spiral 

 cords. 



A typical specimen measures as follows: 



Length 30, diameter 13, last whorl 20, spire 15 mm. 

 Gatu7i Stage: Gatun, C. Z. 



Phos mexicanus Bose Plate 9, figures 10, II 



Phos mexicanus Bose, 1906, Bol. de Inst. Geol. de Mexican, numero 

 22, p. 38, pi. 4, figs. 18-21. 



