330 



PROCEEDINGS OF THE ACADEMY OF 



[1880. 



July 6. 



The President, Dr. Ruschenberger, in tlie chair. 

 Eleven persons present. 



July 13. 



The President, Dr. Ruschenberger, in the chair. 

 Six persons present. 



July 20. 

 The President, Dr. Ruschenberger, in the chair. 

 Ten persons present. 



July 27- 



The President, Dr. Ruschenberger. in the chair. 

 Eleven persons present. 

 The death of Constantine Hering, M. D. was announced. 



Fresh-water Sponges of Fairmount Park.^Mx. Potts reportetl 

 that he had found in a small stream within the limits of the late 

 Centennial grounds, Fairmount Park, Philadelphia, three distinct 

 species of Fresh-water Sponges, one of which appears to be un- 

 described and the others ditfer in important points from the pub- 

 lished descriptions. In anticipation of a more detailed paper 

 describing; these and some other forms which had come under his 

 notice, he said — that one of tliese known as the common green 

 sponge of this neighborhood, resembles the European Hjwngilla 

 Jacusfris in its general appearance and in the shape of its skeleton 

 and dermal spiculae ; but differs in that the seed-like bodies or 

 spherulfe are entirely smooth, showing no incrustation of curved 

 spined spiculae as described in the European species. 



The second form was first seen as a thin rust-colored incrusta- 

 tion, afterwards discovered to consist of spherulfe forming a 

 continuous layer. Supposing this to be new he had named it 

 provisionally S. Morgiana : but later examinations of the living- 

 sponge had convinced him that it was identical with the N. fragilis 

 of Leidy. 



The third was found creeping upon and around Aimcharis and 

 Willow roots, matting them together and thus forming loose, ir- 

 regular masses several inches in diameter ; color yellowish, light 

 or dark green, according to exposure to the light. Spherulae, 

 globular, light yellow or brown, rather numerous amongst the 



