98 AUSTKALIAN LAUD SHELLS. 



The preceding description is copied from the original. Reeve remarks 

 that it is quite of a distinct type. The spiral ridges are not delicate 

 raised lines, but strongly sculptured ridges, with the interstices 

 flatly grooved. Cyclostoma orbiculatum of Benson is regarded by 

 Reeve, who had the great advantage of comparing the original 

 specimens, as being merely a smooth variety, which indeed might 

 almost have been inferred from the descriptions, and I have, there- 

 fore, given that name as a synonym. 



235. Cyclophorus orbiculatus. Pfr. Plate XVI. Fig. 5, 

 copied from Reeve. 



Reeve, Cone. Icon. sp. 101. 



Cyclostoma orbiculatum. Benson, Ann. and Mag., Nat. Hist., 1853, 

 Yol. XI., p. 106. 



Shell excavately umbilicated, orbicularly depressed, whitish ; whorls 

 spirally ridged, and grooved at the sutures and around the umbilicus, 

 smooth between ; aperture small, circular, lip simple. 



Diameter, greatest - 16 ; least - 13 ; height - 08 of an inch. 



Habitat. Shores of Swan River, Western Australia. Bacon. 



Reeve, whose description of this .species I have given above, doubts if 

 this is anything more than a smooth variety of Cyclophorus liricinctus, 

 as he found obvious traces of the spiral grooves and ridges, and next 

 the suture and around the umbilicus they are more decided. 



Genus 



DERMATOCERA. H. and A. Adams. 



Shell globose-conical, narrowly umbilicated, not keeled ; 

 whorls rounded ; aperture sub-circular ; peristome reflected, 

 shortly expanded, with distant margins, borders sometimes 

 united by a thin callus. Operculum membranous, closely 

 whorled, flat. 



Animal with a conical horn, and protected by an epider- 

 mis on the posterior part of the foot. 



* D. vitrea. 



236. Dermatocera vitrea. Lesson. Plate XVI. Fig. 2, 2 a. 



Fig. 3 spotted variety, copied from Reeve. M.C. 



Dermatocera vitrea. Lesson. Pfr., Mon. Pneum. Yiv., Suppl. prim., 



1858, p. 78. 

 Leptopoma vitreum. Lesson. Pfr., Mon. Pneum. Viv., 1852, p. 101. 

 Leptopoma vitreum. Lesson. Reeve, Cone. Icon. sp. 15. 

 Cyclostoma vitrea. Lesson, Voy. de la Coquille, p. 346. Plate XIII. 



Fig. 6. 

 Shell globosely-conical, rather thin, oblicpiely striated, and more 

 finely decussated with minute spiral lines, rather shining, white ; 

 spire sharply conical, apex acute ; whorls 5, convex, last very large, 



