FAUNA OF ORTHAULAX PUGNAX ZONE. Ill 



TEGULA (OMPHALIUS) EXOLETA Conrad. 

 Plate 16, figs. 15, 16. 



Monodonta exoluta (sic) Conrad, Proc. Acad. Nat. Sci. Phila., vol. 1, p. 309, 



1843 (err. typ. pro cxolcta). 

 Monilia exoluta Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 569, 



1863. 

 Turho heliciformis Heilprin, Trans. Wagner. Inst., vol. 1, p. 113, pi. 16, 



fig. 55, 1887. 

 Chlorostoma (Omphalius) exoletum Dall, Trans. Wagner Inst., vol. 3, 



pt. 2, p. 388, pi. 17, figs. 4, 4a, 1892. 



Oligocene of the Tampa silex beds, Ballast Point, and of the 

 lower bed at Alum Bluff, Chattahoochee River, northwest Florida, 

 and Miocene of the Carolinas; Burns. U. S. Nat. Mus. No. 112572. 



The Monodonta kiawahensis of Tuomey and Holmes should be 

 compared with this species, which does not appear in the Pliocene 

 of the Caloosahatchie, nor in the living fauna of Florida. A variety 

 limatum^ is reported from Alum Bluff and the Chipola marl. 



Genus CALLIOSTOMA Swainson. 



Calliostoma Swainson, Mai. pp. 218, 219, 351, 1840. Type, Trochus 



sizyphinus var. conuloides Lamarck. 

 Ziziphinus Gray, Syn, Brit. Mus., 1840. (nude name.) 



CALLIOSTOMA METRIUM Dall. 

 Plate 15, fig. 8. 



Calliostoma metrium Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 394, 

 pi. 22, fig. 27, 1892. 



Oligocene of the Tampa silex beds at Ballast Point, and of the 

 Chipola marl, near the county bridge over the Chipola River, Cal- 

 houn County, Florida ; Dall. U. S. Nat. Mus. No. 113025. 



CALLIOSTOMA TAMPICUM, new species. 



Plate 4, fig. 1. 



Shell small, with 7 flattened whorls, an inconspicuous suture, and 

 flattish base; the nucleus is smooth and projects perceptibly upward; 

 the subsequent whorls show 5 subequal and equally spaced spiral 

 ridges more or less distinctly beaded; on the last whorl and a half 

 these ridges become reduced to small threadlike proportions, hardly 

 rising above the surface of the whorl, not beaded, and separated by 

 wide interspaces with occasional still smaller intercalary threadlets; 

 the periphery of the whorl is bluntly rounded and produced back- 

 ward; the base is flattened and spirally sculptured with 10 or 12 

 obscure spirals which might be regarded as flattened threads sepa- 

 rated by narrow striae, the whole more or less obsolescent; (the aper- 



1 Dall, Trans. Wagner Inst., vol. 3, pt. 2, p. 388, 1892. 



