100 CYCLOSTREMA-YITRINELLA. 



C. SPIRULA, A. Ad. PI. 34, figs. 25, 26. 



Very widely umbilicated, planorbular, spire excavated, whorl? 

 rapidly increasing, spirally striated, with a sloping, smooth sutural 

 margin, last whorl becoming disjointed ; aperture large, round, outer 

 margin of periphery crenate. Dimensions not stated. 



Philippines. 



C. SUBDISJUNCTA, H. Adams. PI. 34, fig. 27. 



Widely umbilicated, spire somewhat elevated, suture deep, white, 

 subpellucid, with numerous spiral riblets, the interstices very mi- 

 nutely longitudinally striate ; whorls 3i, rounded, rapidly increasing, 

 the last solute and descending in front; peristome continuous, simple. 



Diam. 10 mill. Ceylon. 



Subgenus THARSIS, Jeffreys, 1883. 

 C. ROMETTENSIS, Seguenza. PL 34, fig. 28, 



Imperforate, solid, polished, white ; whorls somewhat convex, with 

 well-impressed suture; aperture round, peristome simple, continuous, 

 but slightly appressed, columellar margin callously reflected over 

 the umbilicus. Diam. 2 ! 25 mill. 



European Atlantic, Mediterranean. 



Subgenus GANESA, Jeffreys, 1883. 

 C. NITIDIUSCULA, Jeffreys. PL 34, fig. 29. 



Rimate, opaque, rather glossy, with remote, flexuous growth striae, 

 peristome sharp, simple, interrupted by the parietal wall. 



Diam. 312 mill. 



Between the Hebrides and Faroe Is., 570 fms. 



C. PRUINOSA, Jeffreys. PL 34, fig. 30. 



Narrowly rimate, semitransparent, frosted by minute numerous 

 white tubercles, which are partly embedded in the substance of the 

 shell, on one specimen there are slight spiral lines below the suture; 

 whorls 4, swollen, rapidly increasing, suture deep. 



Diam. 3*75 mill. 



European Atlantic (Porcupine Exped.) 



Genus VITRINELLA, C. B. Adams, 1850. 



As stated under the generic description, this is probably a group 

 of heterogeneous shells, many of which might be referred to other 

 genera. The resemblance of the following species described by 

 Garrett to Cyclostrema and Daronia is striking. 



