HYPOTRICHIDA 



391 



Aspidisca lynceus Ehrenberg (Fig. 168, a). Body about 45 

 to 50 microns long. Fresh or salt water. 



Aspidisca hexeris Quennerstedt (Fig. 168, h). Body about 

 68 microns long. Salt water. 



Aspidisca polystyla Stein (Fig. 168, c). Body about 36 

 microns long. Salt water. 



Family 5 Psilotrichidae Butschli 



Genus Psilotricha Stein. Body oblong, compressed. An- 

 terior end broad, posterior end more constricted. Two rows of 

 longitudinal cirri; two macronuclei. Peristome very broad. 

 Fresh water. 



Fig. 168 a. Aspidisca lynceus. X220 (After Stein). 



b. A. hexeris. X500 (After Calkins). 



c. A. polystyla. X500 (After Calkins). 



d. Psilotricha acuminata. X170 (After Stein). 



e. Balladina elongata. X600 (After Roux). 



Psilotricha acuminata Stein (Fig. 168, d). Body length 85 

 to 100 microns. Fresh water. 



Genus Balladina Kowaleski. With numerous elongated 

 cirri. Fresh water. 



Balladina elongata Roux (Fig. 168, e). Fresh water. Body 

 32 to 35 microns long by 11 to 12 microns broad. 



References 



Stein, F. 1867 Der Organismus der Infusionstiere. Vol. 2. 

 Stokes, A. C. 1888 A preliminary contribution toward a 



history of the fresh-water Infusoria of the United States. 



Jour. Trenton Nat. Hist. Soc, Vol. 1. 



