CYCLOSTREMA, 93 



mistakes, the locality needs confirmation. There can be no doubt of 

 the identity with this species of C. Beaux, Fischer (fig. 63), a West 

 Indian species. 



C. TRicARiNATA, Smith. PI. 32, figs. 66-68. 



Widely umbilicated, depressed, white ; whorls 5, rapidly increas- 

 ing, spirally lirate, the last whorl acutely tricarinated, the peripheral 

 carina strongest; aperture subhexagonal, peristome acute. 



Diam. 3 mill. Whydah, West Africa. 



C. ROSEOTiNCTA, Smith. PI. 32, fig. 70. 



Moderately umbilicated, rosy white; whorls 4, convex, distantly, 

 slightly, spirally lirate, decussated by faint incremental strife, suture 

 depressed; peristome thin. Diam, 1 "75 mill. 



Whydah, W. Africa. 



C. CARINATA, H. Adams. PL 32, fig. 71. 



Widely umbilicated, solid, with regular, angular spiral carin?e> 

 the interstices radiately sculptured; whorls 4, convex, rapidly in- 

 creasing, the last dilated in front; aperture subcirciilar, peristome 

 thickened, subcoutinuous. Diam. 2'5 mill. 



Persian Gulf. 

 C. ciNGULiFERA, A. Ad. PI. 32, figs. 72, 73. 



Widely, flatly umbilicated, depressed, whorls rapidly increasing, 

 the last encircled by six prominent, very sharp ribs; peristome ex- 

 ternally fluted. Diam. 3*5 mill. 



Philippines, Japan. 

 C. Tatei, Angas. PI. 32, figs. 74, 74a. 



Widely, deeply umbilicated, moderately thin, shining, pearly 

 white, microscopically striated; whorls 4, rounded, flattened and 

 slightly excavated next below the suture, with one, or sometimes 

 two, narrow thread-like keels at the upper part, and strongly keeled 

 round the umbilical region, suture distinct; aperture subcircular, 

 lip simple. Diam. 2*5 mill. 



South Australia. 



" The above is the normal condition of the species ; but examples 

 occur which are thinner and have a greater number of keels, some- 

 times as many as seven or eight. At first I was inclined to regard 

 the many-keeled variety as specifically distinct; but on the examina- 

 tion of a large series by Professor Tate, he assures me that the 

 number of keels varies so greatly that it would be impossible to 

 separate them. The thin hyaline examples with many keels are 

 probably younger shells." 



