NATURAL SCIENCES OP PHILADELPHIA. 415 



While speaking of rhizopods, I may mention that there are two 

 articles on the subject in the last two numbers of the Archiv f. 

 Mikroskopische Anatomie, by F. E. Schulze, entitled Khizopo- 

 denstudien. In these papers several forms are described, which 

 have also come under my observation. 



The difflugian described by Schulze as Quadrula symmetrica, 

 and first noticed by Dr. Wallich as Difflugia symmetrica, with a 

 test composed of quadrate plates, I have also found in several 

 localities in New Jersey. 



A difflugian, with a structureless test, referred by Schulze to 

 the genus Hyalosphenia of Stein, and described by him with the 

 name of H. lata, is the same as the Difflugia ligata of Tatem, 

 which I had referred with several other species to a genus under 

 the name of Catharia. I had not had access to the work in which 

 Hyalosphenia was characterized, and which has priority to Ca- 

 tharia. The difflngians referable to it are as follows: 



1. Hyalosphenia ligata: Syn. Difflugia ligata, Tatem; Catharia ligata, Leidy; 



Hyalosphenia lata, Schulze. 



2. Hyalosphenia papilio : Syn. Catharia papilio, Leidy. 



3. Hyalosphenia elegans : Syn. Catharia elegans, Leidy. 



The amoeban which I have described under the name of Din- 

 amoeba is almost identical with that described by Schulze with 

 the name of Mastigamceba (fig. 1, Taf. xxxv.), and which is pro- 

 bably the same as the Amoeba monociliata of Carter. Dinamceba 

 is, however, devoid of the characteristic flagellnm ascribed to the 

 forms of Schulze and Carter. It may, perhaps, prove to be the 

 same as Dactylosphseriam of Hertwig and Lesser, the description 

 of which appeared in the Archiv nearly at the same time as that 

 of Dinamosba appeared in the published Proceedings of the 

 Academy. The former is described as being invested with minute 

 villous appendages of protoplasm, but the latter is covered with 

 minute bacterium-like spicules, such as are represented to exist 

 in Mastigamceba. 



October 12. 

 The President, Dr. Ruschenberger, in the chair. 

 Thirty-five members present. 



Quercus heterophylla. Prof. Leidy exhibited a branch of Quer- 

 cus heterophylla which he had obtained from a large tree, growing 

 on the farm of Mr. J. I. Bishop, in Burlington County, New Jer- 

 sey. The foliage, he thought, indicated a hybrid between Q. phel- 

 los and Q. palustris. He recommended the introduction of this 

 rare hybrid oak into our city park. 



