AUSTRALIAN LAND SHELLS. 97 



spiral or not spiral, not concentrically striated. The two 

 families, Cyclostomacea and Helicinacea, are distinguished 

 from each other by this last character. 



Fam. I. CYCLOSTOMACEA. Pfelffer. 



Man. Pneum. Viv., 1852, p. 14. Suppl. prim., 1858, p. 14. Suppl. 

 See., 1865, p. 13. 



Operculum distinctly spiral, testaceous, cartilaginous, or 

 horny, with very many sub-equal whorls, or with few 

 rapidly increasing ; remaining characters according to sub- 

 order. 



Sub-fam. II. CYCLOPHOREA. Tfeiffer. 

 Mon. Pneum. Viv., Suppl. prim. 1858, p. 38. Suppl- Sec. 1865, p. 58. 

 Operculum horny, rather thin, devoid of external tes- 

 taceous covering, sub-circular, many whorled, nucleus 

 central, shell turbinated or depressed. 



Genus 



CYCLOPHORUS. Montfort. 



Shell globose-turbinate, depressed or discoidal, openly 

 umbilicated ; aperture circular ; peristome continuous, ex- 

 panded or straight ; epidermis thick. Operculum horny, 

 thin, many whorled, more or less concave externally. 



Animal with long slender pointed tentacles ; foot broadly 

 expanded, not grooved. Woodivard. 



* C. liricinctus. * C. orbiculatus. 



234. Cyclophorus liricinctus. Reeve. Plate XVI. Fig. 4, copied 

 from Reeve. 



Cyclostoma liricinctum. Bens. 

 Cyclostoma orbiculatuin. Bens., Mag. and Ann., Nat. Hist., 1853, 



p. 106. 

 Reeve, Cone. Icon. sp. 100 and 101. 



Shell depressed, orbicular, whitish, spirally ridged, radiately striated 

 in the furrows; spire scarcely elevated, apex obtuse, suture exca- 

 vated ; whorls 3^-, slightly convex, last rounded, encircled by 8 

 ridges ; aperture sub-circular, obliquely angulated above ; peristome 

 straight, acute; umbilicus broad, perspective; operculum horny, 

 thin, spiral. 



Diameter, greatest 0*16 ; least 0*13 ; height 0'08 of an inch. 



Habitat. "Western Australia.- Bacon. 

 H 



