On the Ultimate Structure of Marine Sponges. 329 
| XXXL— On the Ultimate Structure of Marine Sponges. 
By H. J. Carter, F.R.S. &c. 
Tue “ ultimate structure” of the marine is, mutatis mutandis, 
the same as the “ultimate structure” of the freshwater 
Sponges. 
l ZL ‘plete Bà 
January 1859 I expressed doubt as to the position of the cilia 
