36 MIDLAND NATURALIST. 
: . 
B. Fresh Water Sponges in which gemmules have not been 
found. 
Provisionally there are three genera : 
Uruguaya, Lubomirskia and Potamolepis. 
Of these nine genera of Fresh Water Sponges the following five 
are represented in North America: Spongilla, Meyenia, Hetero- 
meyenia, Tubella, and Carterius. 
Parmula with three species has thus far only been reported 
from South America. 
Uruguaya with one species is reported from the rapids of the 
River Uruguay, near the town of Salto 
Lubomirskia with four species has only been reported from 
* Lake Baikal, Central Asia. 
Potamolepis with three species has only been reported from the 
Congo River, Africa. 
We may now proceed to the study of the North American 
species of the five remaining genera. 
I. Genus Spongilla Lamarck, 1815. 
It is well known that the ancient authors placed all the Fresh 
Water Sponges into the genus Spongilla, and Mr. Potts claims that 
Carter is the founder of the genus as it stands to-day ; he says on 
page 182 of his Monograph, ‘‘When the old genus Spongilla of 
authors was subdivided by Mr. Carter in 1881, this term was very 
appropriately restricted to that type which includes the species most 
widely diffused and most frequently noticed throughout the world.”” 
Therefore the genus may read : 
Genus, Spongilla, Carter. 1881. 
Under this genus Fotis enumerates 17 specs some of which 
exhibit varieties. 
_ Among these species five are North American, viz.: 
1. S. aspinosa. Pott 
oc. New Jersey swamps. 
2. S. lacustris. Linn. Widely known as the commonest 
F. . Sponge. He gives the following varities: 
paupercula, lawsoni, abortiva, montana, multi- 
foris and lehighensis. 
3. S. fragilis, Leidy. This is reported from many locali- 
k ties in U. S. A., and it has many varieties. One 
variety called calumeti; Thomas, is reported from 
the Calumet River, near Chicago. 
- S. mackayi, Carter, from Nova Scotia. 
5. S. terrae-novae, Potts, from Newfoundland. 
