447 
Floscularia pelagica, &c. By C. F. Bousselet. 
announced at the November meeting, it was found that an account 
of it had just been published by Mr. W. T. Caiman,* giving it the 
above name. A second account has since been published by Dr. 
0. Zacharias,t who found this same rotifer in 1892 as a pelagic 
inhabitant of the large freshwater lake of Plon, in Holstein. Dr. 
Zacharias has named it Eudsonella pida , but it is so very closely 
allied to some other Eotifers of the genus Notops , that it cannot 
very well be separated without at the same time removing several 
other species of this genus. No doubt the genus Notops needs 
revision. Notops Brachionus and davulatus are illoricate animals 
and have one type of jaws, and Notops hyptopus, minor and pygmseus 
have quite another type of jaws and are loricate. But in order to 
avoid multiplying synonyms, I will in this paper describe the animal 
under the name it has first received. 
The two published accounts and figures hardly do justice to the 
peculiarities of this remarkable rotifer, and are incorrect in some 
particulars. I have had a good opportunity of studying it, and so 
hope to be able to give a fairly complete description, although, 
owing to its minute size, it has proved an unusually difficult 
object. 
Notops pygmseus most nearly resembles Notops minor in shape 
and in having a decided chitinous lorica ; the foot protrudes from 
a circular opening in the lorica high up on the ventral side. Its 
greatest peculiarity are the rich and vivid hues with which the various 
parts of the body are coloured : the stomach is deep blue and green, 
interspersed with orange-coloured oil-globules, while the whole of the 
hypodermis or protoplasmic layer lining the shell, and the other 
organs except the brain, are of a rich rose red. The shell itself is 
colourless (contrary to the statements of Caiman and Zacharias), very 
thin and hyaline, as can be seen by squeezing out the animal. In form 
the lorica is broadly oval with a wide neck, the edge of which is broadly 
scalloped ; it is greatly compressed laterally, and in addition pinched 
in along the dorsal side. 
The foot is long, cylindrical, without a joint, and wholly retractile 
within the lorica, in which position it is usually carried ; it terminates 
in a very small toe. Some friends think they have seen two toes, 
but with the best optical means I have only been able to make out 
one ; if there are two, they are very rarely separated. 
The corona is broadly truncate and bears long vibratile cilia in 
tufts, by means of which the animal swims in a wobbling manner, 
revolving at the same time on its longer axis. The whole of the head 
and corona can be retracted within the lorica by means of two pairs of 
narrow, transversely striated muscles, attached to the sides of the 
shell. The mastax is of unusual form and presents some unique 
* W. T. Caiman, “ On Certain New and Eare Eotifers from Forfarshire,” Ann. 
of Scott. Nat. Hist., 1892, pp. 240-5. 
f Forscliungsberichte aus der Biologischen Station zu Plon, i. (1893) pp. 25-6. 
