164 PATAGONIAN EXPEDITIONS I PAL/EONTOLOGY. 



have seen above, these granulations are present in the Patagonian fossil. 

 On the other hand, there is a Miocene species, S. turritella Dall (1892, p. 

 408, pi. 23, f. 2), from Florida, and even a Pliocene species, Margarita 

 maculata Wood (1848, p. 135, pi. 15, f. 3), which much resemble our species, 

 so that it is impossible to say that the Patagonian shell has a distinctly 

 Eocene appearance. 



Gen. CALLIOSTOMA Swains. 

 95. CALLIOSTOMA PHILIPPII (Ortmann). 



PI. XXX, Fig. i2"'. 



1899 Trochus ph. Ortmann, in: Amer. Journ. Sci., v. 8, p. 430. 



Shell low, conical, not umbilicated. Whorls almost flat, only very 

 slightly convex. Last whorl sharply angular on the periphery; above 

 this angular ridge there are 4 revolving ribs. Lower surface slightly 

 convex, with 5 strong, revolving ribs, the most exterior of them separated 

 from the peripheral ridge by a broad groove. Ribs of lower surface with 

 regular, strong granules ; similar granules seem to have been present on 

 the ribs of the upper part of the whorls. 



Height, 7 mm ; diameter, 1 1 mm. 



Remarks: There already exists a Trochus pliilippii Koch (see : Pilsbry, 

 1889, p. 52), but since our species comes in the genus Calliostonia, no 

 change of the specific name is necessary. 



The upper surface of the whorls is not well preserved in our specimens, 

 so that the characters of the sculpture, especially the granulations, are not 

 plainly recognizable. 



This species differs from T. fricki Philippi (1887, p. 101, pi. 12, f. 7), 

 from the Navidad beds of Chili in the following details: (i) the whorls 

 are slightly convex (in T. fricki perfectly flat) ; (2) the revolving ribs are 

 less numerous (in T. fricki there are 6 on the upper part, and at least 7 

 on the lower part) ; (3) the umbilicus is absent. 



C. pliilippii differs from C. observations in the following particulars : ( i ) 

 the revolving ribs are less numerous (in C. observationis 5-6 in the upper 

 part, 9-10 on the base); (2) the ribs of the base are separated from the 

 periphery by a groove ; (3) there are granulations present. 



Record of specimens : Punta Arenas, horizon III (upper Magellanian) ; 

 2 sp. 



