S'.A. NAT., 
VOL. XVIII. No. 2. 
By TOM IRKDALE. 
47. 
Haplotype Helix cyrtopleura Pfeiffer. 
Shells small with spire flattened^ depressedly subdiscoidal, 
with very wide umbilicus, radially coarsely ribbed, a subordinate 
grained sculpture. From this typical form the shell varies to an 
almost smooth or granulose shell and the umbilicus may become 
sc small that it is hidden by the reflected columella. On the 
other hand it may become elevated so that specimens seem to 
iritergrade with members of Glyptorhagada. 
Key to Species. 
Shell with spire depressed, discoidal, coarsely ribbed (say 45 
in number) umbilicus very wide, mouth nearly 
free cyrtopleura. 
Shell similar but smaller, surface granular as well as ribbed, 
umbilicus narrower phillipsia?ia. 
Shell with spire flattened, coarsely granulosely ribbed irreg- 
ularly, umbilicus narrow, mouth discontinuous 
mazvsoni. 
Shell with spire a little elevated, ribs very fine sloping many 
(say over 60) umbilicus narrower, mouth nearly free 
polypleura. 
Shell with spire depressed, subkeeled, discoidal, ribs coarse 
(about 30) umbilicus wide, mouth large, free 
arcigerens. 
Shell a little more elevated than the preceding one with ribs 
coarser, umbilicus narrower, mouth smaller, more 
rounded, free oligopleura. 
Shell a little elevated, subdiscoidal, strong ribs (about 35) 
umbilicus narrow, mouth nearly free, lips thickened 
radiata. 
Shell more depressed than oligopleura^ costae more distant 
and regular, aperture more rounded lemanu 
Shell small, subdiscoidal, ribs very fine, almost striae, narrow 
umbilicus, not hidden by columella adcockiana. 
Shell similar, spire a little elevated, ribs coarser, umbilicus 
almost closed by reflected columella truca. 
Shell small, spire a little elevated, ribs coarse, umbilicus 
_ open, narrow everardensis- 
Shell with spire a little elevated, granulose throughout in- 
cluding apex, umbilicus medium, mouth open, lips 
very little thickened squamulosa. 
Shell small, conical, spire elevated, ribs fine, umbilicus narrow, 
mouth open zeUpenensis] 
