1 15 
well. The basophilous pharyngeal giand cells occur in especially 
great abundance. They empty their secretion, very deeply stainable, 
by means of densely arranged exits on both sides of the fold. The 
eosinophile secretion, on the other hånd, is conveyed to the free 
edge of the fold. It deserves to be mentioned that large accumulations 
of emptied secretion, which contain an intermixture of both kinds 
of secretion are present in the pharyngeal pocket. This chamber 
connects with the main gut by means of a large centrally placed 
opening. The diaphragm is thick and very muscular. As the phar¬ 
yngeal pocket takes up most of the Space inside the muscular wall 
of the body, the main gut is a dorso-ventrally depressed tube; 
nor is its transverse diameter great. A great number of intestinal 
coeca are given off from the long main gut and they branch 
moderately but do not show any anastomosis. The side branches 
are of special interest, as they form deep pouches on their ventral 
side. The assimilation of the food is mainly carried on in these 
pouches, while the dorsal wall of the coeca does not appear as a 
syncytial mass. Thus we have here a differentiation of the branch- 
ing system of the intestine in distributing canals and from these 
projecting ventral thickwalled pouches, where the later stages of 
digestion work can be continued undisturbedly. • 
Genital organs: Ovaries as well as testes lie dorsally, and 
are intermixed. However, there is a certain tendency in the testes 
to lie more ventrally, although numerous testes may extend as high 
as the ovaries; that is, reach the dorsal muscular wall of the body. 
Thus the genital giands are situated between this musculature and 
the intestinal coeca, and, consequently, are exclusively in the dorsal 
half of,the body. As a matter of faet, this dorsal location of the 
testes is a very unusual feature in Polyclads. In Åcotylea it is found 
in a few Leptoplanids, and in the family Stylochidae Laidlaw has 
found a similar location in some Siylochus-s^Qc’xQS. His attempt 
(1903) to use this feature as a basis for classification of the genus 
in question, so rich in species, has been rejected by Meixner (1907). 
In Leptostylochus the dorsal location of the testes establishes the 
possibility for the intestinal branches to have numerous ventral 
projections. This faet and the dense grouping of the intestinal coeca 
can probably be considered the real reason for the concentration 
of the genital giands into one single dorsal layer. The gonads are 
8 * 
