256 SYSTEMATIC PALEONTOLOGY 



Superfamily RHIPIDOGLOSSA. 

 Family TROCHID/E. 



Genus CALLIOSTOMA Swainson. 



Calliostoma BELLUM (Conrad). 



Plate LXI, Fig. 1. 



Trochtis hellus Conrad, 1834, Jour. Acad. Nat. Sci. Phila., vol. vii, 1st ser., p. 137. 

 Zizyphinu& bellus Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 569. 

 ZizypMnus bellus Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), p. 15. 

 Calliostoma helium Dall, 1893, Trans. Wagner Free Inst. Sci., vol. iii, pt. ii, p. 395. 



Description. — " Shell conical, with prominent beaded spiral striae ; 

 whorls slightly contracted above; periphery rounded; base with about 

 eight large beaded elevated spiral strias. Length half an inch." Con- 

 rad, 1834. 



Height, 16 mm. ; diameter, 14 mm. 



Occurrence. — Calvert Formation. Plum Point. 



Collections. — Maryland Geological Survey, Wagner Free Institute of 

 Science, Cornell University. 



Calliostoma philanthropus (Conrad). 

 Plate LXI, Figs. 2, 3. 



Trochus philanthropiis Conrad, 1834, Jour. Acad. Nat. Sci. Phila., vol. vii, 1st ser., 



p. 137. 

 Trochus phllantropus Tuomey and Holmes, 1856, Pleiocene Fossils of South 



Carolina, p. 117, pi. xxvi, fig. 3. 

 Trochus philaniropns Emmons, 1858, Geology of North Carolina, p. 272, fig. 167. 

 ZizypMnus philanthropus Conrad, 1863, Proc. Acad. Nat. Sci. Phila., vol. xiv, p. 569. 

 Zizyphimis philanthropxis Meek, 1864, Miocene Check List, Smith. Misc. Coll. (183), 



p. 15. 

 Calliostoma philanthropus Dall, 1892, Trans. Wagner Free Inst. Sci., vol. lii, pt. ii, 



p. 390, pi. xviii, flg. 9a. 



Description. — " Shell subcorneal, with the whorls slightly angular 

 near their base; and with prominent spiral beaded lines, alternating in 

 size; striae on the base nearly smooth, not crenulated; subumbilicated ; 

 aperture obliquely quadrangular." Conrad, 1834. 



This is one of the commonest and most variable of all the species of 

 Calliostoma in the Atlantic Coast Miocene. The typical forms have 

 three prominent beaded spirals with sometimes intermediate smaller 



