458 W. N. F. WOODLAND ^ 



or ventrally but pointed in lateral view ; shape variable. 

 Genital organs " like those of C a r y o p h y 1 1 a e u s '. Post- 

 ovarian vitellaria present. Eggs measure 54-66 microns 

 in length and 38-48 microns in breadth. Parasitic in the 

 intestine of C a t o s t o m u s c o m m e r s o n i i , Michigan, 

 U.S.A. 



C. filiformis, Woodland, 1923. 



Length of body measures 7-5-24 mm., with breadth (maxi- 

 mum) 1-2 mm. The body is broadest in its posterior half, 

 the anterior half (or third) being attenuated and usually 

 filiform or ribbon-shaped ; the body posterior to the head 

 region is oval in transverse section. The hind end of the 

 body is bluntly rounded. The head region is highly con- 

 tractile, is more or less pointed in front, is narrow, always 

 more flattened than the body posteriorly, and varies in 

 form from a thin pointed filament or ribbon to a tapering 

 wrinkled digitiform structure ; longitudinal grooves are 

 absent. Genital apertures in last seventh of the body- 

 length ; the cirrus aperture is distinctly separated from 

 the vagino-uterine aperture, and there is no atrium. 

 Post-ovarian vitellaria are entirely absent. Eggs (in 

 balsam) measure 62- 2-69- 5 microns in length and 29-2- 

 82-9 microns in breadth. Parasitic in the intestine of 

 Mormyrus caschive, L., Anglo-Egyptian Sudan. 



Archigetes appendiculatus, Ratzel, 1868, and A. 

 brachyurus, Mrazek, 1 908. 



Both of these species possess ' caudal ' appendages, the 

 former an appendage about equal in length to the rest of 

 the body, the latter an appendage only about one-sixth 

 the length of the rest of the body. A. appendi- 

 culatus varies from 2-5 to 3 mm. in length, and is parasitic 

 in the body-cavity of Limnodrilus hoffmeisteri 

 and Tubifex rivulorum, Europe; A. brachy- 

 urus is 5-6 mm. long and is also parasitic in the body- 

 cavity of Limnodrilus hoffmeisteri. The genital 

 organs of these two species apparently resemble those of 

 C a r y o p h y 1 1 a e u s . 



Wenyonia virilis, Woodland, 1923. 



Length of body varies from 11 to 52-5 mm. and maximum 

 breadth from 1-5 to 3 mm. The l)ody is external!}^ divisible 

 into four distinct regions--a broad-pointed head region, 

 a narrow elongated testicular region, a dilated uterine 

 region, and a normally long narrow tapering post-ovarian 



