Paleontology Zorritos Formation 43 



lip tliick, and reflexed above, furnished within with a few 

 rather strong teeth. Inner lip with two plaits near the 

 center, the upper one being much the stronger. There is 

 also a plait at top of the lip, small but quite distinct. Canal 

 wanting. Aperture prolonged into a short, open sinus. 

 Length, 17.4 mm. ; length of spire, 4.4 mm. ; breadth 10 mm. 

 This species closely resembles Aphera tesselata Adams, but 

 is distinguished from that species by its less slender form, 

 stronger cancellating ridges, by its shorter and more open 

 aperture, and by the third fold at the top of the columellar 

 lip." — Nelson, 1870. 



As noted by Nelson ,a ver^^ close relative of this species is 

 A. tesselata Sowerby, which is now living on the west coast 

 from the Gulf of California to Chile. C. dariena Toula,^* 

 from Gatun, is similar, excepting the lack of the reflexed 

 inner callus characteristic in peruana, and its coarser sculp- 

 ture, with the longitudinal ribs missing near the aperture ; 

 they are complete in peruana. 



Cancellaria (Aphera) islacolonis Maury ,^' from the Lower 

 Miocene of Santo Domingo, is the closest known fossil 

 relative. It differs in having finer sculpture, and in the 

 aperture, the outer lip of which is more deeply crenate than 

 in peruana. 



Zorritos formation. Zorritos. 



Superfamily Rhachiglossa 



Family ^^lARGINELLIDAE 



Genus Marginella Lamarck 



Marginella incrassata Nelson 



Plate I — Fig. 9. 

 Marginella incrassata Nelson, Trans. Conn. Acacl., vol. 2, p. 

 197, pi. 6, figs. 5, 6, 1870. 



**Jahrb. k.k. geol. Reiche., Bd. 58, p. 703, pi. 28, figs. 2a, b, 1908. 

 "Bull. Amer. Pal., vol. 5, No. 29, pp. 65-66, pi. 10, figs. 12a, b, 

 1917. 



