PALEONTOLOGY ZORRITOS FORMATION 93 



quadrate, the outer lip sharp, the columella covered with 

 callus. Height, 8; diameter, 10.75 mm - 



This species is somewhat similar to two Floridian shells, 

 C. linulum Dall, 84 from the Calloosahatchie Pliocene and 

 C. palmeri Maury, 85 from the Chipola marl. The differences 

 between these two species are small, hardly of specific value. 

 C. noduliferum is clearly of the same strain, having the 

 same typical sculpture of alternating beaded lines, and the 

 general appearance characteristic of the Floridian species, 

 but it is much larger, has convex, not flat whorls, and has 

 two more beaded spirals to the whorl. 



Zorritos formation. Zorritos. 



Class PELECYPODA 



Order PRIONODESMACEA 



Superfamily NUCULACEA 



Family NUCULJDAE 



Genus LKDA Schumacher 



Leda peruviana Dall 



PLATE V Fig. i. 



Leda acuminata Nelson, Trans. Conn. Acad., vol. 2, p. 205, pi. 7, 

 fig. 8, 1870 (not von Buch, 1845). 



Leda peruviana Dall, Trans. Wag. Inst, vol. 3, pt. 4, p. 579, 

 1898. 



Leda balboae Brown and Pilsbry, Proc. Ac. Nat. Sci. Phila., 

 vol. 63, p. 362, pi. 27, fig. 8, 1911. 



Shell of medium size, delicate, elongate, inflated. Anterior 

 margin produced, rounded, the dorsal part straight and the 

 ventral part rounded; ventral margin arcuate, the lowest 

 point well before the median line of the beaks. Posterior 

 margin produced, the marginal angle acute and the posterior 



84 Trans. Wag. Inst., vol. 3, pt. 2, p. 404, pi. 8, fig. 7a, 1895. 

 85 Bull. Amer. Pal., vol. 4, No. 10, p. 32, fig. 4 of pi. 8, 1910. 



