6 AKT. y. 1. llvEDA : THREE NEW AND 



the microscope that the epidermal surface is uniformly covered all 

 over with closely set cilia. No ventral hook is present. The 

 body-cavity, which extends through nearly the entire length of 

 the body, is laterally compressed in relation to the considerable 

 thickening of body-wall on the sides. In the anterior part of 

 the body-cavity there are present four large funnels belonging to 

 the vas deferens. The alimentary canal is not a continuous tube 

 fixed at both ends to the body-wall, but is represented by a 

 number of small isolated vesicles. 



With these general remarks I will proceed to put down the 

 results of my microscopic studies on the male. 



The Body-wall. — This is of a very considerable thickness and 

 is composed of live distinct layers, viz., the ej)idermis, the dermal 

 musculature, the trabecular layer, the subperitoneal musculature 

 and the peritoneum. 



The epidermis [ep., figs. 8, 10, 11, lo) consists of very tall 

 and narrow cells arranged side by side in a layer. The nucleus, 

 rod-like in shape, is situated near the base of the cells. In fig. 

 8, which shows a part of a paratangential section through the 

 body-wall, there is seen externally to all the structures the 

 epidermis, which, being obliquely cut, presents a crowd of strongly 

 stained nuclei in the basal parts. The cilia on the epidermal 

 surface are developed, as already indicated, uniformly all over 

 the body. 



The dermal musculakire, directly underlying the epidermis, 

 consists of an external system of transverse and an internal system 

 of longitudinal muscle fibers. The two systems are in direct 

 contact with each other. Both are so very tliin and the fibers 

 composing them so fine that, in sections passing vertically through 



