G. WESTERN ON SOME FOREIGN ROTIFERS. 423 



The drawing of this Rotifer has long excited my curiosity, and a 

 few weeks back it occurred to me to get some Nebalia, the marine 

 Entomostracan, on which it is parasitic (or more correctly com- 

 mensal), for examination, and on the first I looked at I found 

 several specimens which agree very well with the figures and des- 

 cription given. It is certainly a Rotifer, but a most extraordinary 

 one, and is well worth looking for. As the Nebalia came from 

 Plymouth and the Channel Islands, this species may also be added 

 to the British list. 



Next I have one or two remarks as to the presence of antennje 

 or seise. These I bring forward simply as the result of my own 

 observations. They may be easily verified or otherwise, and I 

 wish it to be understood that 1 have no desire to pose as a critic 

 of the work already done, and well done, by our authorities on the 

 Rotifera ; I mostly refer to doubtful matters which it is desirable to 

 clear up for the benefit of future students, and a little discussion 

 on such points would, I think, add much to the interest of our 

 meetings here. Pond hunters are many amongst us, but we hear 

 too little of the results of their labours. 



As to the presence of antennae or tentacles, Dr. Hudson's note at 

 p. 139, Vol. ii., of the Rotifera, says *Hhey are in two pairs." 

 This rule may be applied very generally. They are to be found in 

 most Rotifers, and although there are a few exceptional cases, it 

 will mostly be found that they have not been described because not 

 particularly looked for. Again, better objectives and more per- 

 fect methods of illumination are at our disposal than when the 

 description of many of the species was written. But in some 

 cases it is positively stated that they are not present. 



In Lacinularia socialis, ventral antennae are said to be absent, 

 though Dr. Hudson adds a note that " possibly they may be very 

 minute setigerous pimples, which have escaped observation." They 

 are certainly present, and fairly prominent too. How they have 

 escaped observation so long is a mystery to me. 



In Megalotrocha alhojiavicans, in which species also they are 

 supposed absent, they will be found a very prominent feature. 



In the CEcistes the dorsal antenna, probably a double one, will 

 almost invariably be found, although its absence is included 

 amongst the general characters of this genus. 



In Copus cerberus the absence of the lateral tentacles has been 

 made a specific character, but they are invariably present, though 



