50 THE NAUTILUS. 
SYNOPSIS OF THE SUBDIVISIONS OF HOLOSPIRA AND SOME RELATED 
GENERA. 
BY W. HaepDALE. 
Genus Hotospira Martens; type H. pilocerei Pfr. 
Subgenus Holospira s. s. 
Axis large, with an internal fold in the penultimate whorl and 
with a parietal, basal and peripheral lamina projecting into the 
lumen of that whorl. Besides the type, this includes H. goldfusst 
Menke and H. goniostoma Pfr. 
Section Bostrichocentrum Strebel & Pfeffer, 1880. 
Axis moderate, with a continuous plait, except in the last part of 
the last whorl; no lamine. Type H. tryoni Pfr. H. veracruzianus 
Dall belongs here. 
Section Haplostemma Dall, 1895. 
Axis moderate, with, in the penultimate whorl only, a short, 
stout axial lamina extending about half a gyration, but no other 
lamine. Type H. mearnsii Dall, New Mexico. 
Section Eudistemma Dall, 1895. 
Penultimate whorl with a parietal and a short axial lamina only, 
axis moderate. Type H. arizonensis Stearns. 
Section Distomospira Dall, 1895. 
Penultimate whorl with a basal and a short, strong axial lamina 
only, axis moderate. Type H. bilamellata Dall, New Mexico, 
Subgenus Metastoma Strebel & Pfeffer, 1880. 
Axis smooth, without plaits, penultimate whorl without internal 
lamine. Type H. remeri Pfr. This includes also H. pasonis Dall, 
H. coahuilensis Binn., H. semisculpta Stearns, H. pfeifferi Menke, H. 
remondii Gabb., HE. crossei Dall, H. pilsbryi Dall. 
Subgenus Celostemma Dall, 1895. 
Axis vertically ribbed as in Celocentrum, shell otherwise as in 
Metastoma. Type H. elizabethe Pilsbry. 
The internal characters of the following species are unknown: 
H. gealei A. Ads., H. imbricata Martens, H. cretacea Pfr., H. micro- 
stoma Pfr. and H. teres Menke. 
