216 THE MICROSCOPE. 
nounce that all indebtedness has been cleared off, and the Society 
will convene in Buffalo with a balance to its credit. There are, 
however, a number of members still in arrears for dues and they are 
reminded that it is the annual dues on which the Society relies for 
its support. . 
ACKNOWLEDGEMENTS.—From Fred. Gaertner, M. D., Pittsburgh, 
Pa., slides of anthracotic tissue; from John Kruttschnitt, New 
Orleans, La., slides of vegetable tissue. 
ZOOLOG Y.* 
Some Lirriz-known Rortrers. (Pterodina truncata.)t-—Dr. © 
W. Barnett Burn says in regard to this rotifer that the late Mr. 
Gosse saw but one specimen of it, which he found in the “black sea” 
at Wandsworth, and assigns that 
the reason for its so seldom com- 
ing to notice is probably due to 
its habitat. It appears to live 
in a semi-parasitic state on the 
water wood-louse (Asellus vulgar- 
is). He found four of these 
rotifers just in the central line, 
between the legs of the asellus, 
arranged in order, the front of 
each one to the head of the ani- 
mal, and overlapping like scales. 
These never quitted their situa- 
tion, and, what made it certain that they were in permanent quar- 
ters on their host, among the feet of the rotifers, but not attached 
in any way, there were three eggs, glued to the body of the asellus. 
One rotifer was on the side of the animal, and three others were 
swimming in the water, which they did in a graceful manner, not 
very quickly, but with ease, turning the foot from side to side, then 
coming to anchor and making their sucker a pivot, swimming round 
but soon moving off again. On being frightened, foot and head 
disappeared with great rapidity. This rotifer is most like a 
brachionus in the genus pterodina, being much thicker than the 
others, as is shown in the side view, Fig. 1. Moreover the organs go 
*Under this heading will be included all Abstracts relating to the Embryology, Histo- 
logy, ete., of Vertebrates and Invertebrates. ‘ 
+Hardwick’s Science Gossin, May, 1589, page 104. 
