ATTEMPT TO KE-CLASSTFY THE ROTIFERS. 347 



suggestion, I believe, but one that has found wide acceptance. 

 On the other hand, he could not see Floscularia's (fig. 11) 

 tube, could not make out the striated muscles in any Rotifer, 

 could see no difference between the muscles and the nerves, and 

 doubted the existence, as specialised structure, of either the 

 one or the other. He denied, also, that there was good reason 

 for believing that any of the red spots were eyes. 



But although he has small claim to be considered either an 

 original or an accurate observer of the Rotifers, his classifi- 

 cation has one happy hit. He formed his primary groups 

 according to their various modes of locomotion. This pro- 

 duces three orders — Rotifers that are fixed ; those that swim 

 only; and those that both swim and creep like a leech. 

 The first includes the Floscules and Melicertans ; the second, 

 the Brachionse, Euchlanidota and Notommata; and the 

 third, the Philodinsea. The arrangement is excellent, and 

 requires only to be supplemented by the addition of a fourth 

 group to contain Rotifers (like Pedalion mirum (fig. 12) ), 

 which not .only swim, but also skip by means of real limbs. 



In the details of his system Dujardin often fails, and ob- 

 viously from lack of personal acquaintance with the forms he 

 is classifying. For instance, he places fficistes and Cono- 

 chilus in the same genus, declaring that the only important 

 difference between them is their tube, 



I have already pointed out above how widely the structure of 

 Conochilus differs from that of jNIelicerta (fig. 9), and how 

 closely that of (Ecistes agrees with it. Dujardin could not 

 have made a more unfortunate selection of two Rotifers to form 

 a genus with. He follows Ehrenberg in placing Tubicolaria 

 (a form of the ordinary Melicertan type) in a genus by itself; 

 and he places in the same genus Hydatina (fig. 1) and Syn- 

 chseta (fig. 3), genera whose trochal discs, jaws, alimentary 

 canals, and vascular systems are widely unlike. On the whole 

 however his system has great merit ; and would have had 

 much more, had his knowledge of details been at all com- 

 mensurate with his critical faculty. 



