162 PROCEEDINGS OP THE ACADEMY OF [1879. 



June 17. 

 The President, Dr. Ruschenberger, in the chair. 

 Twenty-eight persons present. 

 The death of Win, Adamson, a member, was announced. 



On Rhizopods occurring in Sphagnum. As an instance of the 

 abundance of Rhizopods frequently found together in Sphagnum, 

 Prof. Leidy stated that he had recently collected some from a cedar 

 swamp near Malaga, Gloucester County, N. J., and in the water 

 and sediment expressed from a small bunch, he had observed the 

 following forms: 



1. Difflugia pyriformis. Var. a. with shell of coarse sand ; 



var. b. with shell of chitinoid membrane with incorporated 

 diatomes and sand. Occasional. 



2. D. acuminata. Var. with shell of chitinoid membrane in- 



corporated with variable proportions of diatomes and 

 sand. Occasional. 



3. D. conslricta. Syn. D. cassis. Several varieties. Frequent. 



4. D. arcula. Shell hemispherical, of yellowish chitinoid 



membrane, with incorporated sand ; mouth trilobate. 

 Occasional. 



5. D. globulosa. Small forms. Frequent. 



6. D. spiralis. Rare. 



7. Nebela collaris. Syn. N.numata. Of many varieties, of 



different sizes and proportions. Some in the structure of 

 the shell related with Diffiugia. Abundant. 



8. N. flabellulum. Few. 



9. N. barbala. Occasional. 



10. N. ansata. Occasional. 



11. N. carinata. Rare. 



12. N. caudata. Rare. 



13. N. retorta, n. s. A single active living specimen. Shell 



retort form, nearly like that of Cyphoderia ampulla, but 

 laterally compressed, and having the structure as in N. 

 collaris. Length 0.144 mm., greater breadth 0.072 ; lesser 

 breadth 0.036 ; breadth of mouth 0.027 mm. 

 14 Arcella vulgaris. Few. 



15. A. discoides. Frequent. 



16. A. mitrata. Rare. 



17. Heleopera picta. Occasional. 



18. H. petricola. Less frequent than the former, but more so 



than previously observed. Shell incorporated with vari- 

 able proportions of sand. 



19. Quadrula symmetrica. Occasional. 



