1887.] natural sciences of philadelphia. 293 



July 12. 

 Mr. Charles Morris, in the chair. 

 Nine persons present. 



July 19. 

 Mr. Thomas Meehan, Vice-President, in the chair. 

 Nine persons present. 



August 2. 

 Mr. Charles Morris, in the chair. 

 Eight persons present. 



August 9. 

 Dr. W. S. W. Ruschenberger, in the chair. 

 Eleven persons present. 



The Publication Committee reported in favor of publishing a 

 paper entitled "On the Structure and Classification of Mesozoic 

 Mammalia," by Henry F. Osborn, in the Journal of the Academy. 



On an Aquatic Larva and its Case: The following from Miss 

 Adele M. Fielde, dated Svvatow, China, April 25, 1887 was read: 



Daring last January, I found on the level surface of the coarse 

 sand which covers the bottom of an aqueduct near here, under an 

 inch or two of clear running water, little structures resembling a 

 gray net spread to catch fish, or a tiny cave wilh a gauze awning 

 stretched over the entrance. The arches had a span of from an 

 eighth to a half an inch and always opened toward the current: 

 They were to be seen in scores, with a butti'ess of coarse sand in 

 the rear, and a minute aperture in the floor. The force of the 

 stream had in a few cases swept away the buttress leaving the arch 

 of gauze, with gray filaments, streaming from its torn hinder edge. 

 The occupant of the wee grotto was in every case a caterpillar, not 

 more than five-eighths of an inch long. It burrowed in the sand of 

 of the floor, stretched its head fortli vertically, and fed upon what 

 had been caught in the delicate roof of its den. 



Its head, and the three thoracic segments, each of which bore a 

 pair of four jointed legs ending in two hooks, were of a glossy 

 brown, while the following eight segments were either gray or green, 

 and the terminal segment translucent white. The terminal segment 



