256 HENRY L. OSBORN. 



over the vitelline duct and passing backward toward the posterior 

 end of the body. The course of the uterus is unlike that of any 

 described member of this genus, and is shown in detail in Fig. 

 i, where however the coils are somewhat simplified for the sake 

 of clearness. The course is first a forward loop on the left side, 

 then on the same side a loop running to the hind end of the 

 body, having on its return part a side loop down into the space 

 between the twotestes, then another loop across the front of the an- 

 terior testis, then the uterus crosses to the right side and forms first 

 an anterior loop and finally a long posterior one, at last passing 

 across in front of the ovary and ventrally to and between the two 

 vitella and then dorsally over the ventral sucker to reach the 

 genital pore. There is hardly any atrium (Fig. 3), the male and 

 female ducts meeting almost as they reach the surface. The 

 terminal part of the uterus is ciliated like that of the ductus 

 ejaculatorius. The ova measure 0.052 mm. x 0.050 mm. 



The vitellaria lie close together near the center of the body. 

 They are lobed, each consisting of about three parts, one in the 

 center and one in front of this and one behind it. These are not 

 separate follicles, but lobes of a single organ. 



Of the generic identity of this form with Phyllodistomum of 

 Braun, '99, there can be no doubt. The specific distinctness is 

 equally clear. As it is the first form to be reported from this 



country I propose the name americanum to designate the species. 



* 



PART II. 



Since the foregoing part of this article was written an article 

 has been published by Stafford, '02, on the American Represen- 

 tatives of Distoniuni cygnoidcs, in which a new form is described 

 under the name of Gorgodcra translucida, which bears a consider- 

 able resemblance to P. americanum. I have also had an oppor- 

 tunity which I owe to the kindness of Professor Stafford of ex- 

 amining some specimens of the species he has described. 



The transparency so noticeable in Stafford's form is also notice- 

 able in some of my specimens. My material is derived from two 

 sources, first from worms found by an assistant (Mr. C. C. Tyr- 

 rell) in the laboratory and at once (except one studied alive) 

 placed in corrosive sublimate solution, which are all opaque, and 



