262 BIOLOGY OF THE PROTOZOA 



characteristic, the flagelhim being retained or discarded. Nutrition 

 autotrophic or heterotrophic. 



Three sul)divisi()ns, here gi\'en the vahie of Tribes, are recog- 

 nized : 



Tribe A. Chkysapsidin^, Pascher. With undifferentiated chro- 

 matophores in the form of a network or in diffuse chimps; stigma 

 present, also contractile vacuole; nutrition holophytic and holozoic: 

 reproduction by longitudinal division; spine-bearing cysts known 

 in one species. One genus only, Chri/sapsis, Pascher (Fig. 124). 



Tribe B. EucHROMULiNiNiE, Pascher.— With distinctly differ- 

 entiated chromatophores and soft naked bodies without definite 

 pellicle; many types with delicate loosely-fitting houses {Kephyrion, 

 Pascher), others with thick shells {(^hrysococcns). Pseudopodia 

 formation is characteristic, the pseudopodia lieing used for ingestion 

 of solid food bodies and in some cases forming a crown about the 

 base of the flagellum {Cyrtophora, etc., Fig. 94, p. 200). In other 

 cases the flagellum is withdrawn and fine branching pseudopodia 

 take its place (Chrysopy.vis, Stein). Budding frequent. 



Tribe C. Mallomonadin^, Pascher.— This group includes soli- 

 tary and colonial {ChrysosphwreUa) forms with thick, closely 

 attached membranes with superficial granules (Microglena) or 

 silicious plates (MaJIoiiionas-), the latter bearing, in some cases, 

 long silicious needles (Mallonionas, Chrysosphoerella). The monads 

 usually have a somewhat complicated vacuole system consisting 

 of an apical, non-contractile vesicle and a few contractile vacuoles 

 scattered here and there about it (Fig. 125). Cysts are known for 

 a number of species but reproduction is very little known. 



FainUy 2. Isochrysidae, Pascher.— Little-known forms; solitary or 

 colonial, with two equal flagella at the apical end of the cell; the 

 individuals secrete a jelly in Syitcryjda rolvo.v (gelatinous matrix 

 being absent in the colonies of Sy ultra and in the ]>and-form colonies 

 of Chlorodesmus). Tests with stalks are present in Sfylochrysalis, and 

 without stalks in Derepyxis Stokes, in which the body is attached 

 to the inside of the test by delicate protoplasmic processes. 



Family 3. Ochromonadidae, Senn.— Chrysomonads of simple struc- 

 ture with two flagella, one of which, primary, is longer than the other 

 (secondary) ; they are either solitary or cok)nial with a more or less 

 plastic body and with a widespread tendency to form delicate 

 loose-fitting tests. The vacuoles are simple and pusules or non- 

 contractile vacuoles are absent. 



Sub-family Ochromonadince, Pascher. — Here are included the 

 naked, solitary or colonial forms without specialized pellicular 

 structure, membranes or tests. The gelatinous colony forms are 

 the most characteristic especially the relatively large (up to 400 n) 

 Uroglena and Urocjlenopsis types (Fig. IS, p. 39). These aggre- 

 gates are so delicate that they go to pieces easily in water mains, 



