458 STANLEY C. BALL 



belonging to the genus Graffilla are furnished with "eine mach- 

 tige Bursa seminalis" (receptaculum seminis.) 



In order to classify Paravortex cardii Hallez ('09) presents 

 the following table which brings out more clearly, as I think, the 

 generic differences between Paravortex and Graffilla. 



1. A single ovary. Body more or less flattened (2) 



Ovaries and vitellaria paired (3) 



2. Ovary large, irregularly lobed. Genital pore posterior Anaplodium 



Ovary small. Genital pore at the beginning of the last quarter of 

 the body Didymorchis 



3. Vitellaria unbranched CoUastoma 



Vitellaria branched or reticulated (4) 



4. Genital pore posterior (5) 



Genital pore ventral in the first half of the body (6) 



5. Intestine lobed. A pharynx Syndesmis 



Intestine straight. No pharynx in adult Fecampia 



6. A bursa seminalis Graffilla 



No bursa seminalis ' Paravortex 



From Hallez's key it appears that there is a disagreement 

 as to whether the ovaries and vitellaria in Paravortex should 

 be considered as one organ. Von Graff asserts that they are 

 united, while Hallez considers them separate. From his descrip- 

 tion of P. cardii it is evident that Hallez is correct. 



In comparing the genera Paravortex and Graffilla Hallex 

 says, "Les genres Graffilla and Paravortex ont entre eux des 

 affinites tres etroites. La seule difference vraimente importante 

 qui existe entre ces deux genres c'est I'absence chez Paravortex 

 de la hours seminale qui se recontre dans toutes les especes de 

 Graffilla." 



From a consideration of the several descriptions and keys 

 quoted above one may summarise the distinction between the 

 two genera Graffilla and Paravortex in the following manner: 



Graffilla Paravortex 



1. Two extremely long cylindrical 1. Two club-shaped ovaries. 



ovaries. 



2 Genital pore ventral, not anterior 2. Genital pore ventral, anterior to 



to the middle of the body. the middle of the body. 



3. A large and distinct bursa seminalis 3. Bursa seminalis lacking. 



(receptaculum seminis). 



4. No vestibule between pharynx and 4. Vestibule. 



mouth. 



