NOTES ON SOME FREE-SWIMMING ROTIFERS. 233 
NOTES ON SOME FREE-SWIMMING ROTIFERS. 
By J. E. Lorp. 
T was not my intention to send any further “ Notes” on the 
above subject, but since my last article appeared I have been 
receiving communications from many unknown correspondents, in 
several cases accompanied by tubes of Rotifers, upon which my 
opinion was desired. Mr. T. Bolton, F.R.M. g) the well-known 
microscopists’ provider has been particularly kind in this respect. 
Two or three free-swimming forms, which have thus been brought 
before my notice, I have thought worthy of being included in a 
~ fourth and last communication, seeing the amount of interest which 
many naturalists are just now exhibiting in these animals. One 
very peculiar form, of which Mr. Bolton sent me drawing and 
description only, is of some interest on account of being a new 
creeping form. In this particular it recalls the two genera 
Ichthydium and Chetonotus, which were, on very slender grounds, 
included by Ehrenberg among the Rotifera, but which, from the 
absence of a rotatorian organization, were degraded to the Infusoria 
by Dujardin. From the drawing it appears to be somewhat fusi- 
form, with the back convex, and the under-surface concave ; ciliated 
anteriorly ; t tail-foot forked; it has also four prominent tactile 
organs, one pair on the neck, and another pair on the posterior 
part of the back.. When mature, it is covered with a gelatinous 
sheath, through which the terminal setze of the tactile organs just 
protrude. Unfortunately, Mr. Bolton’s figure does not clearly 
indicate the internal organs, and it does not show any mastax at 
all; however, as Dr. Hudson has named it Votommata spicata, he 
must have been satisfied upon these two points. From the same 
source I received a large, handsome Brachionus, which Mr. Bolton 
believes to be ZB. amphiceros. If it be that species it is much larger 
than “Pritchard” makes it, and it has a remarkable peculiarity 
not mentioned by that authority. His description, too, is very 
meagre, it being dismissed in seventeen words. The peculiarity 
to which I refer is, that the four long, posterior spines are not 
rigid extensions of the lorica, like the anterior ones, but are so 
attached as to be movable, and the Rotifer can cross the points of 
all four of them, while freely swimming, and the lorica too is so 
thin that the animal can bend down the sides at the posterior 
(where it is normally very broad) until they are parallel. If these 
points are confirmed by other observers, they will form two good 
specific characters, as I am not aware of any other Brachionus 
having these two peculiarities. 
In Fig. 26, I have drawn an interesting Rotifer which Mr. Bolton 
