398 ASTRALIIiN^. 



Shell Irochiform, depressed ; whorls convex, rugose, la- 

 mellated, the last often angulated and with hollow sphiose 

 scales round the periphery; axis perforated, sometimes 

 covered by a callous deposit; aperture sub-quadrate, ar- 

 cuated, sub-truncate anteriorly. 



Si/n. Imperator, Mont/. Hercoles, Mont/. Can- 

 thorbis, Swams. Tubicanthus, Swains. 



Ex. A. heliotropium, Martyn, pi. 44, fig. 3. Oper- 

 culum, A. calcar, Linncens, fig. 3, a, 3, b. Shell, A. 

 solare, Chemnitz, fig. 3, c. 



Species of Astralium. 



aster, Phil. heliotropium, Martyn. 



calcar, Li^in. Phcebia, Bolt. 



cicatrosum, Jonas. planum, Gmel. 



costulatum, Latn. solare, Chem. 

 heliacum, Phil. 



Genus STELLA, Klein. 



Operculum thick, with a slight convexity over the axis, 

 outer edge thin, axis perforated. 



Shell trochiform ; spire elevated, whorls with radiating, 

 spiny scales, axis imperforate ; aperture sub-circular ; co- 

 lumella rather flattened, iucrassated, continuous anteriorly 

 with the outer lip. 



Si/n. Cyclocantha, Sioains. Calcar, Mont/ Sol, 

 Klein. Stellaria, Schmidt. 



Ex. S. Spengleriana, Chemnitz, pi. 44, fig. 4. Oper- 

 culum, S. stellata, Chemnitz, fig. 4, a, 4, h. Shell, S. 

 Spengleriana, fig. 4, c. 



The shells of this group are solid, spinose, and trochi- 

 form, with the axis imperforate. The species are chiefly 



