BY GUNSON THORPE, R.N., M.R.C.S. 29 
So rich is the water of the above ponds in beautiful microscopic 
organisms, that it would be impossible in one paper to give even 
the most cursory description of all of them. The rotifers or 
rotatoria, are alone selected for description. 
I. Family “ Flosculariade.” 
1. Floscularia ornata. Not uncommon. 
II. Family “ Melicertadz ” 
1. Melicerta ringens. Common. 
2. Limnias annulatus, common. This rotifer is rare in 
England ; Dr. Hudson says that he has seen it but once, 
and then had no time to study it, (Hudson & Gosse on 
“ Rotifera,” Vol. L, page 77). Mr. Whitelegge of the 
Australian Museum, Sydney, writes to me the following : 
—“L,. annulatus is found in England and America, and 
also here, (N.S.W.) It is not very common anywhere. 
The tube is usually a light horn colour and ringed 
throughout, without any visible structure, or rather, 
particles of foreign matter, such as is seen in most other 
tube-dwelling rotifera. When kept in an aquarium for 
a few weeks, the tube is quite transparent.” ‘The animal 
has five horny processes on the dorsal surface of its 
head, two above, and three below, and it is probable 
that the pressure of these against the case, is the cause 
of its being ringed. When the animal is about to 
extrude the undigested portions of its food, the move- 
ment of the mastax becomes much slower, or stops 
altogether. Immediately afterwards a sort of eversion 
of the intestine takes place, and a transparent tube is 
thrust upwards as high as the rotatory disc, the fecal 
matter being extruded right into the cilia, and so carried 
away. (A living specimen of this rotifer was exhibited 
under the microscope at the meeting.) 
III. Family “ Philodinade.” Rare. 
1. Actinurus neptunius. Common. 
IV. Family “ Triarthrade.” 
1. Polyarthra platyptera. Rare. 
V. Family “ Dinocharide.” 
i. 
Scaridium longicaudum. Common. 
VI. Family “ Salpinade.” 
1. Diplois Daviesiz. Rare. 
