220 THE ROYAL SOCIETY OF CANADA 



Ji. A gonad on each side of body. 



Ki. A single vas deferens, passing along inner side of ovary 



and opening near oviduct. Sypho7iotethis. 

 K2. Vas deferens or vasa deferentia opening into atrial 

 cavity near blind end of ovary, that is, not accompanying 

 the latter. 

 Li. Pharynx with folds. 



Ml. Oviduct directed toward atrial aperture. Caesira. 

 Mo. Oviduct directed anteriorh/, that is, away from 

 atrial aperture. Lithoneplirya. 

 L2. Pharynx without folds. 



Ni. Stigmata present. Oligotrema. 

 N2. Stigmata absent, Hexacrohylus. 

 J2. A single gonad, situated on the right side. Gamaster. 



In order not to burden the present article unduly we have neither 

 indicated the synonym\' of the various species, nor given references 

 to the original descriptions, except in a few cases. Practically all 

 the references not given can be found in Hartmeyer's account of the 

 family in Bronn's Tierreich, Bd. Ill, Suppl. pp., 1316-1329, to which 

 the reader is referred. 



Species which we have personally been able to examine for this 

 study are indicated with an asterisk (*), 



EUGYRÎNAE sub-fam. nov. 



This sub-family shows a very general tendency for the stigmata 

 that form the infundibula not to become sub-divided as development 

 proceeds. This is well shown in the genus Eugyra and is responsible 

 for the name. In Rkizomolgtda, Eciorchis, and Molgidoides more or 

 less subdivision occurs. In HalomoJgula, which is doubtfully assigned 

 to this group, subdivision has been carried to an extreme. 



In two of the genera {Eugyra and Eugyrioides), representing 

 difïerent sub-groups, the pharyngeal folds fail to develop into the 

 condition characteristic of the family, the post-larval condition of a 

 single longitudinal bar for each row of stigmatic coils remaining 

 throughout life. 



The dorsal tubercle rema'ins for the most part very simple, in 

 many cases not showing more than a simple funnel-shaped aperture. 

 Where the aperture becomes slit-like and bent it takes the form of a 

 simple horse-shoe with the opening between the horns usually directed 

 anteriorly or to the left. 



