248 G. A. and W. G. MacCallum, 



make tliis out and it is present in relatively few specimens and 

 then often only in the anterior portion subdividing five or six of 

 the transverse grooves. It is important, however, witli legard to 

 the systematic position of the worni. 



Along- the margins lying between each two suckers there are 

 small prominences which indicate the position of the curious flask 

 shaped tactile organs. In section it is found that these lie in little 

 sacs embedded between the suckers and open in a funnel shaped 

 depression on the surface of the protruding- hillock. The neck of 

 the flask like structure is richly supplied with circular muscle fibers 

 which extend down part way over the bulb. There is a narrow 

 lumen which widens at the bottom into a bulbous structure with 

 clear or slightly granulär contents. Evidently the organ can be 

 protruded or perhaps everted through the cuticular oriflce. Its 

 nervous connections are not evident and one is led to question its 

 purely tactile character. It gives rather the impression of a secreting 

 gland like apparatus. The cuticle is rather thin and is smooth and 

 unarmed over the whole body. The body musculature is fairly well 

 developed in the usual arrangement and the parenchyma is loose 

 and relatively poor in nuclei. The ventral muscular body wall is 

 continued back past the anterior border of the ventral sucking disc 

 to join the body wall again behind it so that the body cavity is 

 divided into two parts of which the dorsal contains the intestine 

 and the distal portions of the genital tract while the ventral w^iich 

 forms the seat of the sucking disc contains the genital glands. It 

 is as though the body were composed of two tubes, one inside the 

 other with one w^all, the dorsal in common. 



The genital pore pierces the ventral body wall just in front 

 of the ventral disc and the Uterus and ejaculatory apparatus open 

 side by side. 



The mouth opens as described at the anterior end of the body 

 without any deflnite sucker. When the cephalic lobes are turned 

 backward, as they generally are, the niouth becomes terminal and 

 is found to lie surrounded by a portion of the root of these muscular 

 lobes which may serve as a kind of muscular lip. 



There is a quite long prepharyngeal tube with thin wall and 

 only a few circular muscle fibers. The pharynx is strong with the 

 usual muscular layer and flattened laterally so that in cross section 

 the lumen is a slit. Behind this the Oesophagus quickly assumes 

 the character of the intestine which is a simple unforked tube with 



