Protozoa and Rotifera <it TIavana, III. 323 



of a dicliotomously branching pedicel ; anterior extremity 

 prolonged into a spine-sliaped process on cue side. Flagella 

 two, one much shorter than the other. Nucleus and con- 

 tractile vacuole usually conspicuous. 



24. A. vegetans 0. F. MiJLLER. 



A number of colonies were found in an aqaarium started 

 with mud from the dry bed of Phelps Lake. 



Subfamily DiNOBRYONINiE. 

 DiNOBRYON EhrBG. 



Animals in transparent loriciE, which are united into 

 branching colonies. Free-swimming; zooids with a long and 

 a short dagellum, an anterior pigment spot, and two lateral 

 chromatophores. 



25. D. sertularia Ehrbg. 



Very common and often extremely abundant in the tow- 

 ings, especially from waters containing vegetation, during the 

 period from December to June. 



26. D. sertularia divergens Imhof. 

 Observed in May, in towings from substation C. 



27. D. sertularia angulatum Seligo. 

 Abundant in the towings from Dogfish Lake in ApriL 



28. D. sertularia undulatum Seligo. 

 Common in the river towings from E during April. 



Suborder EUGLENOIDINA. 



Family EUGLENID^. 



EuGLENA Ehrbg. 



Animals free-swimming, generally oval to elongate, usually 

 obtuse anteriorly, and more or less prolonged and attenuate 

 posteriorly. A well- developed mouth and flagellum at the 

 anterior end, and near this end a red pigment spot. Color 

 usually green. 



In the latter part of summer Euglcna is universally abun- 

 dant, even in the smallest pools and ditches. At certain 



