326 Illinois State Laboratory of Natural History. 



38. T. urceolata Stokes. 



Rare ; found during September in towings from the river 

 at E. 



39. T. torta Stokes ('88). 



Observed only in September, in towings from the river and 

 Dogfish Lake. Not common. 



40. T. hispida Stein. 



Found in towings from Dogfish Lake in September. 



Family CHLOROPEL.TIDID.ffi. 



PHACUS Nitzsch. 



Persistent in shape, ellipsoidal to pyriform, mostly com- 

 pressed and leaf-like, with a posterior, pointed, tail-like pro- 

 longation ; cuticle indurated, longitudinally or spirally 

 striated; mouth and throat asymmetric, opening dorsally; 

 body green, with anterior pigment spot. 



41. P. triqueter Ehrbg. 



Scarce ; found in September in towings from the river 

 channel. 



42. P. pyrum Ehrbg. 



Found but once, namely, in a towing from the river chan- 

 nel in October. 



43. P. longicauda Ehrbg. 



This fine and attractive species was present in small num- 

 bers from June to September, and was generally distributed. 

 A single occurrence in October is also on record. 



Suborder ISOMASTIGODA. 

 Family CHRYSOMONADIDiE. 



Synura Ehrbg. 



Individuals oval to elongate, each contained in a membra- 

 nous lorica, commonly united into free-swimming subglobose 

 colonies ; llagella two, subequal ; one or more colored eye- 

 spots. 



