6 THE AMERICAN MONTHLY [Jan., 



face as marble, and utilized in the erection of stately 

 buildings, just as similar beds formed long ago are used 

 in our day. It would seem that their presence in lakes 

 and ponds might ultimately fill them up ; but just how 

 they would act in the flowing waters of rivers is not so 

 easy to answer. 



Amoeba princeps, verrucosa, and radiosa have been 

 found. The first named species was obtained in large 

 numbers only once, on which occasion a paper was read 

 before the Society stating some new facts then observed. 

 Since then search has been made for Amoeba in the hope 

 of witnessing a recurrence of these things and further 

 developments thereof, but without result thus far. Phe- 

 nomena of this kind, it may be, occur only at particular 

 seasons. There is no doubt, but that others who keep 

 on the watch will sooner or later see the same things 

 and be able to verify them. The probability is that a 

 great deal more than is suspected still remains to be 

 learned concerning Amoeba. 



Elegant and remarkable forms of the Rotiferge are 

 always present. Philodiua, Rotifer, Brachionus, Actin- 

 urus, Notholca and Pterodina usually appear each sea- 

 son, but not in great numbers. Melicerta ringens ap- 

 pears now and then. The beautiful Floscularia may be 

 found by careful search of the under side of pond-lily 

 leaves. An individual captured this year, deposited a 

 cluster of no less than a dozen eggs at the base of its 

 tube. It was the intention to keep these and watch 

 their development, but they were unfortunately lost. 



Apsilus lentiformis is, perhaps, one of the most re- 

 markable of the Rotiferae. It was captured in October 

 this year, only six or eight being found on the under side 

 of a lily leaf. It had previously been found only a few 

 years ago on the leaf of a similar plant in a little pond 

 at Mr. Elliott's greenhouse. This Rotiferon appears to 

 be never abundant and the microscopist who is success- 



