82 HUXLEY, ON DYSTERIA. 



the notice of Mr. Dyster or myself. It would appear that 

 tlie "apparatus" disappears^ and is reproduced during fission^ 

 for in the single case observed_, mere rudiments of it were to 

 be seen in each half of the strongly constricted mass. 



Dysteria has not hitherto been observed to become en- 

 cystedj although this condition has been carefully sought for. 



There can, I imagine, be little doubt as to the true sys- 

 tematic position of Dysteria. The absence, in an animal 

 which takes solid nutriment, of an alimentary canal with 

 distinct walls, united vnth the presence of a contractile 

 vesicle, with the power of transverse fission, and with cilia 

 as locomotive organs, is a combination of characters found 

 only in the Infusoria. In this class, again, the existence of a 

 sort of shell or lorica, constituted by the structureless outer 

 layer of the body ; the presence of a submarginal ciliated 

 groove around a large part of the margins of the body ; and 

 the inequality of the two lateral halves, leave no alternative 

 save that of arranging Dysteria near or in the Euplota of 

 Ehrenberg. 



Indeed there is one species figured by Ehrenberg {' Infu- 

 sions-thierchen,' p. 180, pi. 42, fig. xiv), Ettplotes macrosty/ns, 

 found at Wisniar, on the Baltic, which, in general aspect, and 

 in the possession of a foot-like appendage, so closely resem- 

 bles the present form, that were it not for the absence of any 

 allusion to the amethystine globule, or to the " apparatus," 

 I should be strongly inclined to think it identical with 

 Dysteria. That an internal armature is not inconsistent with 

 the general plan of the EvpJota, is shown by Chlamidodon, 

 whose apparatus of styles would probably repay re-exami- 

 nation. 



Notwithstanding certain analogies which might be shown 

 to exist between the manducatory apparatus of some Rotifera 

 (see, e. g., that of Fnrcularia marina, figured by Mr. Gosse, 

 in his excellent memoir, 'Phil. Trans.,' 18k)) and the 

 "apparatus" oi Dy.steria, 1 see no grounds for regarding 

 the latter as in any way an annectant form between these 

 groups. 



