206 PROCEEDINGS OF THE ACADEMY OF [1887. 



film of the above S. bohmii, ample for comparison with the next 

 species, *S'. novce terra-, which, in one point, it most curiously resem- 

 bles. Having given above the very clear description by Dr. M. 

 Hilgendorf, it is needful only to explain that while such a "layer of 

 parenchyma" around the gemmule as that seen in its associate spe- 

 cies, S. nitens, is absent, the gemmule of aS'. hohmii is provided with 

 a thick "granular crust" beneath which the gemmule spicules are 

 embedded, a capsule of skeleton spicules enveloping the whole. 

 The dermal or flesh spicules, as he describes them, are niinute biro- 

 tidates, nearly resembling those of tS. novce terrce and Meyenia everettl, 

 but somewhat larger than either: the shafts are more frequently 

 bent and a bolder enlargement at each extremity gives origin to more 

 widely spreading hooked rays. I incline to the opinion that the oc- 

 casional inflations of the shafts of these spicules as well as of the 

 spicules of the gemmule, indicate a want of full maturity in the spec- 

 imen when gathered. 



My interest in the description given of this little species by Dr. 

 Hilgendorf was such as to induce me to ask, through Mr. Carter, the 

 opportunity of making a personal examination of it ; more j^artic- 

 ularly, to discover whether in it, as in >S'. novce terrce, the birotulate 

 dermal was associated with a gemmule acerate showing any tendency 

 toward a birotulate form. This I find is no more the case than in 

 several other species o^ Spongllla ; S. j'ragills for instance, Avhere there 

 is also a grouping of recurved ra}' s near the extremities. 



The curious fact that a coincidence of type has here associated the 

 Island of Newfoundland with Central Africa, will not escape the 

 notice of any one ; nor that a corresponding form in a neighboring 

 genus should only appear, as 3'^et, in places so remote as a corner of 

 Massachusetts and the Lakes of Nova Scotia. 

 (17) Spoagilla novae terrae. Potts. I'roc. Acad. Nat. 8ci. I'liila. ISSl, p. 228 otc. 



Sponge encrusting ; sarcode of the young growth, a dense mass of 

 minute spherical cells, embedding slender, curving lines of fascic- 

 ulated skeleton spicules, developing later into a very loose, open tis- 

 sue, with few conne(;ting spicules. 



Gemmules ratlier numerous, unusiuilly large, spherical; chitinoas 

 coat thin; crust apparently wanting. 



Skeleton spicules relatively few, slender, cylindrical, smooth or 

 sparsely microspined ; gradually poiiited. (See cut.) 



Dermal or flesh spicules very abundant, minute birotulates of un- 

 equal size; shafts slender, cylindrical, occasionally spined ; outer 



