254 ^- A. and W. G. MacCallum, 



process quite to the apex of tlie ridge between the sucker like de- 

 pressions. 



The body of the worni is curiously divided by a miiscular wall 

 which extends from the end of the groove which marks off the 

 sucker from the body anterioi'ly, backward to fuse in the parenchyma 

 of the posterior extremity. Forward it is quite thick and prominent 

 in the section but it becomes mach more delicate posteriorly. It 

 Is composed largely of longitudinal muscular flbers together with 

 abundant circular flbers which run to merge in or form part of the 

 general circular nnisculature of the body. They are the direct 

 continuation of the circular flbers of the neck and iudeed practically 

 none go into the formation of the suckiug diso, which in this 

 sense might seem to be rather outside the general body. Never- 

 theless the male and female genital glands lie ventral to this parti- 

 tion and the yolk gland may extend far into the tissue upon which 

 the sucker itself rests. 



The Uterus and vas deferens perforate this partition in the 

 hinder part of the body, however, so that their distal portions with 

 the seminal vesicle and the ejaculatory apparatus come to lie dorsal 

 to it and to open just above and anterior to its Insertion into 

 the body wall at the anterior margin of the root of the 

 sucking disc. 



The body musculature in general is very delicate, the raost 

 striking features being the long flbers which run into the root of 

 the sucker and apply themselves to the sucking disc proper. Else- 

 where, except as described about the anterior end of the body, the 

 circular and other flbers of the body wall are of extreme delicacy. 

 The skin, too, is veiy thin and the cuticular layer can be made 

 out as a covering of remarkable tensity. The body parenchyma is 

 very loose and composed of a meshwork of flbers with scattered 

 nuclei, evidently holding a considerable quantity of fluid which in 

 the sections appears as a flnely granulär coagulum, 



There is an excretory sac which opens at the posterior end of 

 the body and which, branching, gives rise to two wide trunks which 

 run forward ventral to the muscular partition and receive excretory 

 tubes from the whole of the body. The specimens are not well 

 enough preserved to enable us to follow accurately these branches. 

 The nervous System is also difflcult to trace but there is a ganglionic 

 mass on each side of the prepharynx quite far anteriorly toward 

 the mouth from which nerve trunks are given off. 



