NATURAL SCIENCES OF PHILADELPHIA. 155 



water, might, under exposure to the air, germinate. He referred 

 to other cases of the springing up of nevv plants after the deposit 

 of fresh earth, and suggested a mode of testing the origin of the 

 seeds. 



Dr. Carson and Mr. Aubrey H. Smith called attention to the 

 great change which, during late 3'ears, had occurred in the vege- 

 tation of the neck below the city. 



On Asplenium ebenoides. Mr. Redfield then alluded to the fern 

 known as Aaplenium ebenoides^ described some years ago b}' Mr. 

 Scott, from a few plants found on the rock}' banks of the Schuyl- 

 kill above Philadelphia. Most of our botanists have doubted the 

 validity of the species, and have supposed it to be an abnormal or 

 hybrid form originating from Gampto^orus rhizophyUu!^ (Walking 

 Fern), and Asplenium ebeneum, both of which species occur abund- 

 antl}' at the locality. Recently a few plants of the same form 

 have been found near Havana, Alabama, by Miss Tutwiler, and 

 in precisely the same suspicious compan}-. Her account ma\' be 

 found in the Bulletin of the Torrey Club for May, 1873. Recently 

 Mr. A. H. Curtiss, of Libertj^, Va., has received from Alabama a 

 frond of this fern, rooting at the apex, precisely as the walking 

 fern does. Mr. Redfield thouo-ht this fact tended to confirm the 

 doubts already entertained upon the validit}- of the species. 



Notice of some Bhizopods. Prof. Leidy remarked that since 

 he had made a communication on Deinamceba mirabilia he had 

 had the opportunity of examining a number of additional speci- 

 mens. All of them appeared to be variegated with twin spots of 

 green, which he found to be due to the scattered joints of tw^o spe- 

 cies of desmids of the genus Didymoprium, swallowed as food. He 

 had observed the animal swallow a considerable portion of a ^\2i- 

 mcuto? Didymoprium Gremllii. In another instance he had seen 

 an individual eject upwards of fift}' joints o^ Didymoprium Bre- 

 bissonii, from three different portions of the body simultaneously. 

 Another peculiarity he had observed in the animal which had pre- 

 viously escaped his notice. The body appears to be surrounded 

 or enclosed in what might be called an atmosphere of minute spi- 

 cules, which can be seen as a circle a short distance beyond the 

 outline of the bod}'. 



Prof. Leidy then presented drawings and descriptions of a 

 number of Difflugians which he supposed to be new. They were 

 mostly found in a pond in Absecom Creek, New Jersey, and in 

 the sphagnum on the border of the pond. Most of the same spe- 

 cies were likewise found in a sphagnous swamp of Longacoming, 

 and in the sphagnum on the border of Lake Hattacawanna, New 

 Jersey. 



DiFFLUGiA VAS. Tcst composcd of angular quartz particles, 

 generally coarse, shape pyriform, with the neck constricted where 

 it joins the body; fundus obtuse; mouth large, circular. Ento- 



