Anatomy of err fit tu Itofi'ferft. 35 



to exnminc by nie«iis of serial sections. After makin;^ a 

 careful study of my soctious 1 soon saw tliat some features 

 wliicli were plainly visible in one Rotifer were often indis- 

 tinguishable or nearly so in the remaining specimens ; hence, 

 I deemed it necessary to gather what remai'ks I had to offer 

 into a single communication. 



Having resided for some years in the neigiibourliood of 

 Epping Forest, v/here, in the numerous ponds, one has no 

 ditiieulty in securing at most times of the year such well- 

 known forms as Melicerfa ringens^ Stephanoceros^ &c., I was 

 astonished on taking up my residence in Cornwall to find 

 these Rotifers absent from the numerous ponds in the 

 county, and at first imagined that a more diligent search was 

 only necessary to secure them. However, after examining 

 during the past two years at fixed intervals a large number of 

 ponds and pools to all appearances most favourably situated, 

 J have, up to the present time, been only able to find Drachi- 

 omis riihens in any quantity. 



Within the past six months I introduced into a pond in the 

 neighbourhood of Falmouth some fine healthy specimens of 

 Melicei'ta conifera procured from Epping Forest. The weed, 

 Chora vulgaris, to which the cases containing the Rotifers 

 were attached, flourished and grew luxuriantly ; but the 

 Rotifers soon died from some cause I am unable to discover. 

 This fact may in some measure be due to the mildness of the 

 climate here, frosts of any degree of severity being unknown. 



The specimens whose structure I have examined by means 

 of serial sections are as follows : — Melicerta ringens, M. coni- 

 fera, Brachionus ruhens, and Lacinularia socialis. 



I propose in the following paper to discuss in as brief a 

 manner as possible the various points of interest that have 

 presented themselves to me during a close examination of 

 sections of the above-named Rotifers, and to refer the reader 

 to Dr. Hudson's monograph (1) * for a detailed account of 

 each species. 



Nervous System. 



Melicerta ringens and M. conifera. 

 (PI. iV. figs. 1-8.) 



A close examination of serial sections has failed to reveal 

 to me any material difference between these two species as 

 regards the structure of the central nervous system. 



M. Joliet (2) was the first investigator who discovered the 



* The numbers refer to Bibliographical List at end. 



3* 



