SPECIAL ANATOMY. 213 
Bulimus. The digestive apparatus in B. dealbatus, 
B. decollates, and B. virgulatus, resembles that of H. 
auriculata; the oesophagus is long, narrow, and dilated 
in the middle ; the stomach is cylindroid, and more or 
less sacculated. The stomach of B.fasciatus resembles 
that of Limax variegata, being large and capacious ante- 
riorly, cylindrical and sacculated posteriorly. The rec- 
tum is capacious and sacculated. 
Pupa. A characteristic of this genus is the very great 
proportionate length of the viscera, corresponding to the 
numerous whorls of the shell. The retractor muscle of 
the buccal mass is long and strong. The dental plate 
has two central, conical toothlets in its cutting edge. 
The oesophagus is very long and narrow. The stomach 
is very long, and e,ven forms a fold upon itself. The rec- 
tum is very long and sacculated ; the muscle on its outer 
side is well developed. 
Succinea. A characteristic of this genus, the re- 
verse of Pupa, is the great breadth and shortness of the 
viscera. The dental plate has an upper, quadrangular 
piece, superadded to the ordinary, crescentic plate. 
The stomach resembles that of Limax variegata. Its 
mucous membrane presents several longitudinal rugae. 
The small intestine does not undergo the same relative 
diminution with the other viscera. The rectum is very 
short, and, from the transverse position of the pulmo- 
nary cavity, it is placed along the right of the breadth, 
