ROTELLIDZ. 301 
aperture circular, varicose; columella not callous. Animal and 
operculum unknown. Its aflinities may be with Ethalia. AR. 
cyclophoreus, Carp. Cape St. Lucas. 
PARKERIA, Gabb. (After C. F. Parker, curator of the Philada. 
Academy.) Shell minute, in form like Rotella, but with the 
shell-substance vitreous and transparent or translucent like 
Vitrinella; inner lip thickened, and the umbilicus covered with 
a not very heavy callus as in Rotella. Miocene; W. Indies. 1 
recent species. &. vitrea, Gabb (xxix, 98). 
TuRBINA, de Koninck, 1881. 
Distr.—4 sp. Carboniferous; Europe. 7. deornatus, Kon. 
Shell top-shaped, thin and fragile, smooth ; spire of 5-8 convex 
whorls; mouth large, transversely rounded, the margin sharp, 
not thickened, columella not twisted; umbilicus narrow and 
deep, sometimes wanting. 
PLocostyLus, Gemmellaro, 1878. 
Distr.—Liassic, Jurassic; Italy. P. typus, Gemm. 
Shell top-shaped, thick, smooth; spire obtuse; whorls rapidly - 
enlarging, the last very large, rounded ; base more or less flat- 
tened; mouth round; inner lip straight, short, ending in an 
anterior fold, forming a tubercle ; outer lip obtuse. 
Trrnostoma, H. and A. Adams. 
Distr.—8 sp. Philippines; Japan, Mazatlan. TZ. politum, A. 
Ad. (xxix, 99). 
Shell orbicular, depressed, subspiral, polished or spirally 
striated, last whorl rounded, or angulated at the periphery ; 
umbilical region covered with a large, flat callosity ; aperture 
transverse ; inner lip smooth, callous; outer lip thin, simple, 
not margined or reflected. 
CALCEOLINA, A. Ad. Shell neritiform, oblong, depressed ; spire 
small; whorls rapidly increasing, umbilical region callous ; 
aperture semicircular ; inner lip with a large wide callus, covering 
posteriorly the umbilicus ; margin of the callus straight, simple. 
Japan. TZ. pusilla, Ads. (Ixxix, 100). 
[ Cyctora, Hall. 
Distr.—C. minuta, Hall. Paleozoic; Ohio. 
Subglobose, thin, small, spire short, consisting of a few whorls ; 
columella smooth, slightly reflected over a minute umbilicus ; 
aperture circular. See p. 223. | 
Anompuatus, Meek and Worthen. 
Distr.—A. rotulus, Meek and Worthen (Ixxix, 1). Carbon- 
iferous; Ills. 
Shell depressed, sublenticular, imperforate, smooth, volutions 
