244 
Proceedings of Indiana Academy of Science. 
First, I must express my pleasure in finding that you had 
sent only Sponges; that is, remembering that frequently even 
workers in other lines of science are utterly unfamiliar with 
these forms, and hence send one gelatinous and otherwise in- 
congruous articles. I was glad to learn that you know a sponge 
when you see it. The only possible exception is in your No. 5, 
which, as you supposed, is not a sponge but only a puzzle, which 
may perhaps be explained by considering the fibres to be a form 
of alga, or more probably, the stems or stipes (as the “Micro- 
graphic Dictionary” calls them) of some, possibly all, those 
Diatoms now found at the outer surface of the sub-spheres. I 
have frequently found Diatoms so growing. 
No. 1 is Carterius tubisperma Mills, and is, I am sorry to 
say, the only sponge in satisfactory condition for safe deter- 
mination. Nos. 2 and 4 are, I fully believe, of the same species 
as No. 1, and they have plenty of gemmules or statoblasts; but 
these are so far from maturity that, if the same species, the 
chitinous coat is extremely thin and it apparently has not yet’ 
developed the foraminal tubules, the granular crust, and protec- 
tive birotulate spicules which should be the determining points. 
I do not understand why this should be so with the date given 
(November 15 and later); but I suppose it possible that cold 
spring water or its unusual depth may have retarded develop- 
ment to a date later than that with which I have been familiar. 
This is further suggested by No. 3, in which I have failed to 
find any gemmules, and which reminds me of the appearance 
and condition of forms that I have sometimes called perennial 
or evergreen sponges, which apparently continue their growth all 
through the winter, at least in deep water.’ 
No. 3 is clearly a different sponge from the others, as shown 
by its shorter and more robust spicules (skeletal), which, as you 
will see, are covered with very minute spines. I should have 
been much pleased to find the stadioblasts of this sponge. The 
skeleton spicules suggest Meyenia leidyi Carter, although in that 
species they are rarely microscopical. You may meet with it 
again under more favorable circumstances.’ 
Although I fear they are too soft for safe transportation, 
I propose to pack with the vials returned, two trial slides, No.1, 
showing Carterius tubisperma, in which you may see the for- 
aminal tubules before mentioned and the armature of radial 
birotulate spicules, beside the skeleton and dermals; and No. 2, 
showing separated spicules of the same. 
>See my Monograph, pp. 245 and 246. 
3 See fig. 1, plate X, of my Monograph. 
