MICRO-ORGANISMS IN SUTTON PARK. 
175 
the beautiful drawings in Dr. Leidy’s splendid Monograph ot 
Freshwater Rliizopods of North America. They afford very 
good examples for studying the question raised by Dr. Wallicli 
in his critique on this work in the “ Annals and Magazine of 
Natural History,” Yol. XVI., 1885, as to the source of these 
markings, some of which are evidently dependent on the 
appropriation of the empty cases of diatoms; but such 
markings as those shown by Dr. Leidy in Difflugia spiralis 
(often present in this locality) are to me inexplicable. It is 
most wonderful that a minute mass of formless jelly, such as 
these animals apparently consist of, should have the power of 
building up these definitely-shaped and elaborately-adorned 
dwellings. 
The specimens of Acanthocystis chcetophora with its bristling 
bifurcate-spine-covered spheres and brilliant green contents 
were numerous, but of Biomyxa vagans I have only found two 
specimens, both on the same slide. 
Infusoria. 
Astasia tnchophora. 
Dinobryon sertularia . 
Uvella virescens. 
Hemidinium nasutum. 
Euglena viridis. 
Spirostomum ambiguum . 
Of the Infusoria, the ringed groups of flagellate monads 
form, I think, a new species. I have seen them only in this 
locality. They look like a ring of choano-fiagellate monads ; 
I have not been able to submit them to a power sufficient to 
make certain of the flagella or collars, but their active motion 
as they swim about, revolving on the axis of the ring, gives a 
fair presumption of their flagellate character. The diameter 
of the ring is of an inch. 
Stentor sp. ( Miilleri ? ). 
Vorticella campanula . 
Ringed groups of Flagellate 
Monads. 
Rotifera :— 
Floscula ria orna ta. 
Ptygura melicerta. 
Philodina acnleata. 
,, citrina. 
Rotifers. 
* 
Notommata spicata. 
Two other allied species. 
Furcularia forficula. 
,, gracilis. 
,, cceca . 
* Described in Hudson andGosseas Copeus spicatus , Copeus labiatus , 
and Copeus pachyurus. Mr. Gosse considers the first to be the 
largest known rotifer. 
