PALEONTOLOGY ZORRITOS FORMATION 41 



base of the body whorl are six to eight spiral cords with nar- 

 rower interspaces; these are most prominent just inside the 

 aperture. The shoulder of the body whorl is sharp, and the 

 sides descend from it, with very little convexity, in straight 

 lines. The aperture is somewhat wide. Height, 73 ; diam- 

 eter, 38.5 mm. 



A number of specimens of this graceful cone occur in 

 Nelson's collection, and a cast in the Singewald collection 

 from the Upper Zorritos formation is questionably identified 

 with it. It is similar to Conus molts Brown and Pilsbry, 32 

 of the Gatun fauna, differing from that species in having 

 straighter sides, lacking the prominent spiral striae on the 

 body w r horl, and in having a proportionally higher spire. 

 It is a much smaller form. It differs from C. vnolis var. 

 bravoi, of the local fauna, as noted in the remarks on that 

 variety. 



Upper Zorritos ( ?). Quebrada de las Alturas. 



Conus molis var. bravoi n. var. 

 PLATE I Fig. 6. 



Conus sp. ind. C. Nelson, Trans. Conn. Acad., vol. 2, p. 194, 1870. 



Shell large, solid, heavy. The spire very low, almost flat 

 except at the apex, where the early whorls rise in a nipple- 

 like peak. Whorls twelve to fourteen in number, the last 

 four or five flat to very slightly concave, the remainder flat 

 to convex. The whorls of the spire are depressed in some 

 specimens at the suture, the edge of the succeeding whorl 

 rising above the suture. Sculpture of moderately arcuate 

 growth-lines on the spire; on the body whorl the growth- 

 lines are prominent on worn specimens ; there is no evidence 

 of spiral sculpture on the spire and upper part of the body 

 whorl; on the lower part of the body whorl are fairly coarse 

 spiral threads. A distinct, thread-like keel marks the outer 

 edge of each whorl ; on the body whorl it marks the apex 



32 Proc. Ac. Nat. Sc. Phila., vol. 63, p. 343, pi. 23, fig. I, 1911. 



