ANATOMY AND HISTOLOGY OF ZLIMAX AGRESTIS, 1538 
matter, but I shall endeavour to keep these parts as brief 
as possible, entering more minutely into such points as 
may seem new. 
In preparing this paper I got the most valuable assis- 
tance from Professor Herdman, D.Sc., and I have great 
pleasure in tendering him my best thanks for his kindness 
shown on this and numerous other occasions. 
GENERAL REMARKS. 
A general account of the anatomy of Limax flavus s. 
variegatus has been written by Rolleston (8), and all the 
details, as far as they are given by that author, apply to 
Limax agrestis. This latter species differs from Lamax 
flavus only in regard to Semper’s organ. For whilst 
Rolleston (provided he is correct) figures this organ on the 
right side of the buccal mass, I find it in Limax agrestis 
in the form of a circle of lobules surrounding the buccal 
mass dorsally and laterally. Further details on that point 
will be given below, under the head “‘ Nervous System.”’ 
Nalepa (7), in his paper on the anatomy of the Stylomma- 
tophora, gives further information about Limaz, while 
dealing, however, primarily with Zonites. We shall have 
to refer frequently to Nalepa’s work, when discussing the 
different systems of organs. 
ALIMENTARY CANAL. 
The literature on the alimentary canal is scattered in 
different papers, Nalepa’s (7) being the most complete 
account. Barfurth (25) and Frenzel (28) have shown that 
the liver consists of three kinds of cells: firstly, ferment 
cells (B.) or club shaped cells (F'.); secondly, liver cells 
(B.) or granular cells (F.); thirdly, calcareous cells (B. 
and F.). The first two kinds of cells enclose granules of fat, 
