218 Proceedings of the Royal Physical Society. 



LIST OF SPECIES. 

 Family Microdinad^. 



Microdina paradoxa, Murray (12). 



The family and species were originally discovered in the 

 higher part of the Forth Valley, at the outflow of Loch 

 Vennachar. Mr Evans found it, in wet moss at Torduff, in 

 the Pentlands, March 1905. 



Family PHiLODiNADiE. 



In anticipation of Mr Bryce's revised classification of this 

 family, I have included all the species in the three old- 

 established genera, Philodina, Callidina, Rotifer. In order 

 to avoid the anomaly of placing species, the close relationship 

 of which is not denied, in different genera, merely because 

 one possesses eyes while the other does not, I have pro- 

 visionally redefined these genera in accordance with our 

 present conception of the affinities of the species. 



Genus Philodina. 



Animals having four toes, and the corona consisting mainly 

 of a pair of wheel-like ciliated discs. The only other animal 

 known, in the order Bdelloida, having four toes, is Microdina, 

 which is separated by the absence of discs, etc. 



A. Eyes present ; oviparoics. 



P. roseola, Ehr. 



On Potamoyeton, Malleny Dam, near Balerno, February. 



P. citrina, Ehr. 



On Potamogeton, Malleny Dam ; Upper Elf Loch, Braid 

 Hills, November ; on Lemna, from Duntarvie Pond, near 

 Winchburgh, December. 



P. erythrophthalma, Ehr. 



Duddingston Loch, March ; Nether Habbie's Howe, Pent- 

 land Hills, March. 



