722 PROTOZOOLOGY 



Penard, E.: (1922) Etudes sur les infusoires d'eau douce. Geneva. 

 Powers, P. B. A.: (1932) Cyclotrichium meunieri, etc. Biol. Bull., 63: 



74. 

 Prandtl, H.: (1906) Die Konjugation von Didiniumnasutum. Arch. 



Protist., 7:251. 

 Roux, J. : (1901) Faune infusorienne des eaux stagnantes de environs 



de Geneve. Mem. cour. fac. sc. l'Uni. Geneva, 148 pp. 

 Sikama, Y. : (1938) Ueber die Weisspunktchenkrankheit bei See- 



fischen. J. Shanghai Sc. Inst., 4:113. 

 Stiles, C. W.: (1894) Report on a parasitic protozoan observed on 



fish in the aquarium. Bull. U. S. Fish Comm. for 1893, p. 173. 

 Stokes, A. C.: C1888) A preliminary contribution toward a history 



of the freshwater Infusoria of the United States. J. Trenton 



Nat. Hist. Soc, 1:71, 

 ten Kate, C. G. B.: (1927) Ueber das Fibrillensystem der Ciliaten. 



Arch. Protist., 57:362. 

 Thon, K. : (1905) Ueber den feineren Bau von Didinium, etc. Ibid., 



5:281. 

 Wenrich, D. H.: (1929) Observations on some freshwater ciliates. 



I. Tr. Am. Micr. Soc, 48:221. 

 — (1929a) The structure and behavior of Actinobolus vorax. 



Biol. Bull, 56:390. 

 Woodruff, L. L. and Spencer, H.: (1922) Studies on Spathidium 



spathula. I. J. Exper. Zool., 35:189. 

 (1924) II. Ibid., 39:133. 



