THE NAUTILUS. 51 
Genus CaLocentrum Crosse & Fischer, 1872. 
Shell decollate, axis pervious. 
Subgenus Celocentrum 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 Bostrichocentrum, not ribbed. Type C. irregulare 
Gabb., Lower California. 
Genus EucaLopium Crosse & Fischer. 
Shell resembling Celocentrum, but large, with a solid axis. 
Section Eucalodiums.s. Type E. ghiesbrechti Pfr. 
Axis sinuous and folded its whole length, except close to the aper- 
ture; transverse series of teeth on the radula long (65:1°65 in 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 
Bulimulus closely related to Leptobyrsus. The genuine Rhodea very 
probably bears an analogous relation to Otostomus. It is vivipar- 
ous, but the Lower Californian species is not. If the latter be 
deemed worthy of a sectional name, Pseudorhodea might be used for 
it. The new species of Ho/ospira mentioned above are described in 
a 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 
obtusa Drap., has recently been investigated by Mr. A. Protz and 
Professor von Martens. It proves to be no Pupa, but a member of 
the Helicide, closely allied to the chalky Helices of Europe known 
as Helicella or Xerophila. 
