10 
York, and a similar number in Nova Scotia and Newfoundland; also 
eight each in Florida and Illinois. In the following decade, (1890—1900) 
Ohio was given a list of ten species, chiefly through the work of D. S. 
Kellicott, who published two small papers on the subject of fresh-water 
sponges. In 1916 the writer published a list of nine species for Michigan, 
this being the number found in connection with his work at the Uni- 
versity of Michigan Biological Station at Douglas Lake, in the northern 
part of the state. In 1918 he also published the description of a new 
species from Oneida Lake, in the state of New York. A study of Illinois 
material collected by various investigators has brought the list for the 
state up to twelve species, which is the maximum number for any state, 
as far as is known to the writer. Almost nothing is known of the sponge 
fauna of any state west of the Mississippi River and, with the exception 
of Florida, almost nothing of the sponge fauna of the southern half of 
the United States. Mills listed four species in lowa, and the writer has 
found four species in the high-altitude lakes near Tolland, Colorado, in 
the vicinity of the University of Colorado Mountain Laboratory. As 
far as is known to him, not more than three species are recorded from 
any other state west of the Mississippi River. He will welcome infor- 
mation concerning more extended lists, if there be such. There is some 
evidence that the sponge fauna of the southern states will be found to 
differ in some respects from that of the northern ones. During the past 
fourteen years, N. Annandale, of the Indian Museum in Calcutta, has 
published numerous and important papers on fresh-water sponges, chiefly 
those of Asiatic regions; a few of them, however, have dealt with North 
American species. He has created one new genus, Asteromeyenia, for 
two of such species, and announced a few new locality records for others. 
His work was based on rather scanty collections belonging to the United 
States National Museum. 
Four North American species were first found and described in 
Europe; while seven species first described in North America were subse- 
quently found in Europe, and at least three of them also in Asia. About 
one third of our species are thus more or less widely distributed in the 
Northern Hemisphere. 
SYSTEMATIC 
Important characters for the recognition of species are toned in the 
spicules of the skeleton ; in other spicules which may or may not be present 
in the sponge mass and are variously designated as flesh spicules, dermal 
spicules, or sarcode spicules; and in still others, known as gemmule spic- 
ules, which are intimately related to the gemmules. The gemmules are 
small seed-like bodies appearing in summer or autumn, and are involved 
in one important method of reproduction. Ina few species the apertures 
of the chitinous walls of the gemmules are at the summit of tubular pro- 
longations, and these in turn are sometimes provided with one or more 
filaments, borne at or near the margins of the apertures. For the posi- 
tive identification of nearly all of our species, the presence of gemmules 
is necessary. 
