104 Lake Maxinkuckee, Physical and Biological Survey 



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 "Micrographic Dictionary" 

 calls them) of some, possibly all, those Diatoms now found at the 

 outer surface of the sub-spheres. I have frequently found Dia- 

 toms so growing. 



No. 1 is Carterius tubisperma Mills, and is, I am sorry to say, 

 the only sponge in satisfactory condition for safe determination. 

 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 ex- 

 tremely thin and it apparently has not yet developed the foraminal 

 tubules, the granular crust, and protective bisotulate spicules which 

 should be the determining points. I do not understand why this 

 should be so with the date given (Nov. 15 and later) ; but I suppose 

 it possible that cold spring water or its unusual depth may have re- 

 tarded development 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 appear- 

 ance 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 . 2 



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 statoblasts 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. 3 



Although I fear they are too soft for safe transportation, I pro- 

 pose to pack with the vials returned, two trial slides, No. 1, show- 

 ing Carterius tubisperma in which you may see the foraminal 

 tubules before mentioned and the armature of radial birotulate 

 spicules, beside the skeleton and dermals; and No. 2, showing sepa- 

 rated spicules of the same. 



2 See my Monograph, pp. 245, 246. 

 'See fig. 1, plate X, of my Monograph. 



