156 LIVERPOOL BIOLOGICAL SOCIETY. 
EXCRETORY SYSTEM. 
Oscar Schmidt (10) states that the kidney of the 
Gastropoda is a sac of which the lining epithelium is 
thrown into lamellar folds, and that these folds form 
either complete or incomplete compartments. Some years 
afterwards, Nalepa (7) asserted that the lamelle of the 
kidney do not divide it into complete chambers, and that 
there are present only folds which reach nearly to the 
centre of the cavity. In this paper, of which I have seen 
only an extract, Nalepa seems to attack mainly Meckel 
(22), who had stated that the kidney is divided into 
complete compartments. According to my preparations 
the statement of O. Schmidt is correct. For I find in all 
sections (longitudinal and transverse) through the kidney 
of Limax some lamellar folds which form complete 
compartments, and also others which form incomplete 
compartments (fig. 3, Pl. X.). 
The granules which are present in every one of the 
epithelial cells are urinary concretions. Sometimes they 
are the size of the nucleus, sometimes they are smaller, 
but occasionally also about twice the size of the nucleus; 
these larger ones are frequently found lying in the cavity 
of the kidney. These excretions have been mentioned by 
O. Schmidt and others. The epithelium of the kidney is 
not ciliated, thus differing from the epithelium in the 
kidney of the Lamellibranchiata and the Nudibranchiata. 
Besides the papers mentioned above, there does not 
seem to be much literature dealing with the kidney of 
Limax. A few years ago Meuron (37) and Jourdain (86) 
studied the development of the kidney, and still more 
recently a paper has appeared by Amaudrut (35), who 
compares the structure and the function of the kidney and 
the lung in the Pulmonata, 
