70 D. BRYCE ON A NEW CLASSIFICATION OF THE BDELLOID ROTIFERA. 



Philodinidae. In my opinion these details form good indices to 

 the functional perfection of the food-collecting organ. 



The four-toed species constitute about one-third of the Philo- 

 dinidae in the present list. I have divided them among five 

 genera, of which three correspond to groups suggested by Murray 

 as already quoted, viz. the " parasitic," the " viviparous and long- 

 spurred," and the "semi-loricate" groups. For these I propose the 

 new genera Embata, Dissotrocha, and Pleuretra respectively. 



For the present I hesitate to separate the " short-spurred 

 species" (of Murray) from the "oviparous." Together they 

 form a fairly compact genus, which includes nearly all tho 

 species assigned by Ehrenberg to the genus Philodina, and for 

 which I therefore retain that generic name. In these four 

 genera the corona is always in close conformity with the family 

 type, and in every case there is a distinct throat or passage 

 to the mastax. In the recently described (P.) intermedia^ 

 de Beauchamp, the corona differs from the type in several details 

 (most notably in the partial absence of the cingulum or secondary 

 wreath), and there is practically no throat, the mastax being 

 placed so closely below the mouth tliat the jaws themselves can 

 be employed in seizing the food. For generic distinction the 

 latter character appears to me to be the most suitable, and I 

 propose therefore to refer to it in creating for this remarkable 

 species the new genus Abrochtha. 



Subsection II., with three toes (the dorsal toe usually close to the 

 terminal pair). The species with three more or less well-developed 

 toes are divided according to their customary course of reproduc- 

 tion. For those which are viviparous I have retained the generic 

 name Rotifer as suggested by Milne (23). This emendation of 

 the distinctive character makes little change in the constituent 

 species. With the exception of the discordant form " ?-oe/>er?," 

 now transferred to the genus Habrotrocha, all the species with 

 rostral eyes are viviparous, and therefore remain in the genus 

 with which they have been hitherto associated, wliilst to their 

 number is added the blind but closely related species " longirostris " 

 Janson, and '^ tnagnicalcarata " Parsons. For those other three- 

 toed species which are oviparous I retain the generic name 

 Callidina, not because the genus as now presented contains any 

 of the eight species described by Ehrenberg, who created the 

 genus (for the opposite is the case), bat because the majority of 



