THE NAUTILUS. 51 



Genus CCELOCENTRUM Crosse & Fiscber, 1872. 

 Shell decollate, axis pervious. 



Subgenus Ccelocentnnn s. s. 



Axis vertically ribbed internally. Type C. turris Pfr. This in- 

 cludes nearly all the known species. 



Subgenus Spartocentrum Dall, 1895. 



Axis as in Boslrichocentrum, not ribbed. Type C. irregulare 

 Gabb., Lower California. 



Genus EUCALODIUM Crosse & Fischer. 

 Shell resembling Ccelocentrnm, but large, with a solid axis. 



Section Eucalodium s. s. Type E. ghiesbrecJtti Pfr. 



Axis sinuous and folded its whole length, except close to the aper- 

 ture; transverse series of teeth ou the radula long (65'1'65 iu the 

 type). 



Section Oligostylus Pilsbry, 1895. 



Axis straight and smooth ; radula narrower (36-1-36 in the type). 

 Type E. blandianum Crosse and Fischer. 



Columna ramentosa J. G. Cooper, which might, from the shell, be 

 assimilated either to Berendtia, Rhodea, or some of the above-men- 

 tioned groups, proves, from the anatomy, to be merely a section of 

 Bulimnlus closely related to Leptobyrsus. The genuine Rhodea very 

 probably bears an analogous relation to Otostomus. It is vivipar- 

 ous, but the Lower California!! species is not. If the latter be 

 deemed worthy of a sectional name, Pseudorhodea might be used for 

 it. The new species of Holospira mentioned above are described in 

 & report on the mollusks of the late Mexican Boundary Survey 

 (1892-4), by the writer, which will appear, properly illustrated, in 

 the report of the Commissioners of the Survey. 



My special thanks are due Mr. H. A. Pilsbry for kind assistance 

 rendered during the preparation of the report. 



The anatomy of a curious cylindrical Austrian land snail, Pupa 

 vbtusa Drap., has recently been investigated by Mr. A. Protz and 

 Professor von Martens. It proves to be no Pupa, but a member of 

 the Helicidce, closely allied to the chalky Helices of Europe known 

 as Helicella or Xerophila. 



