388 Miscellaneous. 
He spoke of the arrangement as a timely step well taken in advance 
in the history of this branch of the animal kingdom. 
He believed that the characteristics of the statospheres and their 
spicula were those which furnished the only reliable distinctions 
among freshwater sponges; but the recent discovery of novel forms 
in American waters had already required an increase in the number 
of genera, and seemed to make it desirable to modify the terms of 
some of those already established. 
In illustration he referred to several forms observed in this 
neighbourhood, resembling in many points the English Spongilla 
lacustris (taken as a type of the genus Spongilla in the new ar- 
rangement), in which, however, the spicula were riot acerate, but 
irregular in shape, were not placed ‘tangentially’ upon the 
surface, or were altogether wanting. Specific names were suggested 
for these, but were held under advisement, awaiting a decision as 
to whether it would be better to create new genera for them or to 
enlarge the scope of those already defined by Dr. Carter. 
The two new genera already decided upon were then described.- 
Under the generic head Meyenia Dr. Carter has grouped those 
species in which the statosphere is surrounded by birotulate spicula, 
radiately arranged, one disk resting upon the surface. Throughout 
the genus as already constituted, the shatts of these spicules are of 
a nearly uniform length, and the outer disks, nearly or quite touching 
at their edges, give the appearance of a second coat to the stato- 
sphere. In two species, however, observed by Mr. Potts last 
summer, this uniform series was broken by another of about double 
their length, much fewer in number, somewhat regularly arranged, 
interspersed among them. He proposed to group these under the 
genus Heteromeyena, as H. argyrosperma and H. repens, suggesting 
that the latter may possibly be the same as Bowerbank’s Spongilla 
(now Meyenia) Baileyr. 
Another new genus had been formed and dedicated to Dr. Carter 
under the name Carterella, to include the singular form described 
by the speaker last year in the ‘ Proceedings of the Academy,’ and 
then called Spongilla tentasperma, changed later to S. tenosperma. 
The distinguishing peculiarity of this genus is that the tube sur- 
rounding the foramen of the statosphere is elongated, and divides into 
from two to five long curling or twisted tendrils, by means of which 
during the winter the statosphere remains attached to the stems or 
roots upon which the sponge had grown. ‘This will now be Car- 
terella tenosperma. 
A second species has been added to this genus, the discovery of 
Professor Kellicott and Mr. Henry Mills, of Buffalo, under the name 
of Carterella tubisperma. In this the tube is much longer than in 
any sponge heretofore described, terminating in several straggling 
rather weak tentacles, much shorter than in the former species. 
The birotulate spicula in the two forms are quite different; and the 
species are unquestionably distinct.—Proc. Acad. Nat. Sci. Philad., 
June 14, 1881. 
