12 
than those with smooth ones, but the distribution is similar; while in the 
Michigan material, specimens with smooth or nearly smooth skeleton- 
spicules are most frequent. . fluviatilis has a distribution similar to 
that of E. miilleri, but is less abundant. 
ILLINOIS SPECIES 
In 1883 Henry Mills, of Buffalo, New York, found in the Calumet 
River, near Chicago, a sponge which he afterwards described under 
the name Pleiomeyenia calumeticus, but which evidently was the form 
of Ephydatia miilleri having smooth skeleton-spicules. In the same paper 
(1884a) he mentions finding Carterius tubisperma in Illinois. 
Mills read before the State Microscopical Society of Illinois, on May 
27, 1887, a paper on fresh-water sponges which recorded eight species 
found in the state, and which was published in full in an issue of a local 
newspaper. Since it contains the earliest definite record of the occurrence 
in the state of some of the species mentioned, that part of the paper which 
describes the localities and gives the details of the collecting activities 
is here reproduced with a few typographic errors corrected. It appeared 
under the general heading, ‘““Fresh Water Sponges”, and with the follow- 
ing subheadings: “Paper by Henry Mills, of Buffalo, read before the 
Microscopical Society”; “Earliest Mention of this Species of Infusoria 
and Difficulty of their Classification” ; “Record of a Scientific Party which 
lately Explored some of the Illinois Lakes”’. 
On the 20th of September, 1886, a party consisting of B. W. Thomas and 
W. H. Summers, members of the State Microscopical Society, Chicago, and 
the writer made an effort to explore some of the lakes in ‘Illinois, north of 
Chicago, with sanguine expectation of being able to add something to our 
list of genera and species of these and other microscopic objects; for, al- 
though the two Chicago gentlemen searched principally for Diatomaceous 
material, the writer gratefully acknowledges valuable help from them in the 
search for the objects of his special pursuit. We left Chicago by the after- 
noon train on the Chicago and Northwestern Railway, arriving at McHenry, 
McHenry County, in time to prepare for an early start up the Fox River in 
the morning. Each of the party had his boat, and collecting apparatus, and 
those who felt like using the oars did so, While those who felt so inclined 
secured others to do the hard work. It was a cloudy and rather cool morn- 
ing, and by the time we reached “Dutchman’s Slough,’ which is the outlet 
of a small sluggish stream or creek three and one-half miles north of McHenry, 
there was a drizzling rain, which threatened to dampen the enthusiasm of 
the party; but as it did not last long, we were soon ready for work. Although 
not immediately successful, there was enough enchantment in the spot and its 
surroundings to inspire us with confidence, and in a short time we reached 
a place in the slough where the sponge could be hauled by the drags, with 
the weeds to which it was attached in large handfuls. The weeds or algae 
upon which the sponge grew consisted of a species of Utricularia, and Ana- 
charis canadensis (both of microscopic interest), and some others not re- 
corded. Unfortunately the sponge, on examination at home with the micro- 
scope, proved to be mostly immature, containing but few statoblasts, but 
enough to determine the species as mostly Carterius tubisperma Mills; Meyenia 
fluviatilis and Meyenia Calumetica Thomas. But in the interest of science 
the spot should be remembered, that future investigators may be benefited at 
least to the extent of our discoveries in this interesting locality. Other micro- 
