The Mastigophora 127 



less Stokesiella (210; Fig. 4. 2, H). A cup-shaped to spheroid lorica bears a slender 

 stalk in Arthrochrysis Pascher (222) and the colorless Arthropyxis (222). The stalked 

 lorica of Poteriochromonas Scherffel (202) is funnel-shaped; that of Stenocodon Pascher 

 (222) is compressed laterally, with an oval mouth. The stalkless lorica of Pseudo- 

 kephyrion Pascher (Fig. 4. 2, D) — including "Kcphyriopsis Pascher and Ruttner" — is 

 cup-shaped. 



Arboroid colonies of loricate flagellates arc included in Dinobryon Ehrenberg (1, 

 202; Fig. 4. 2, A) and its colorless homologue, Hyalobryon Lauterborn (202; Fig. 4. 2, 

 B). In the apochlorotic Codonobotrys Pascher (222). a cluster of individually stalked 

 loricate flagellates is attached to a heavy common stalk. Stylobrynn Fromentel (181), 

 another colorless type, probably belongs to the Ochromonadidae. 



Non-loricate arboroid colonies are assigned to several genera. In Anthophysis Bory 

 and Ceplialothamnion Stein, both colorless genera, the flagellates are attached in 

 clusters at the ends of branching stalks (181). In the colorless Cladonema Kent em. 

 Pascher (Fig. 4. 4, A), MonadodendroJi Pascher (Fig. 4. 4, E, F), and Dendromonas 

 Stein (181), as well as in the pigmented Chrysodendron Pascher (207) which often 

 forms small colonies, the flagellates are attached singly to branches of the stalk. 



More or less spherical colonies are characteristic of several genera. In Uroglena 

 Ehrenberg, including Uroglenopsis (181), the flagellates are embedded in a gelatinous 

 matrix (50). No matrix is evident in Cyclonexis Stokes (Fig. 4. 5, A, B), Skadovskiella 

 KorshikofE (163. 165), Synochromonas Korshikoff (165), or Synura Ehrenberg (165; 

 Fig. 4. 5, C). 



Fig. 4. 8. Prymnesiidae. A. Prymnesium parvum Carter; 

 x2360 (after C). B, C. Platychrysis pigra Geitler, flagellate and 

 amoeboid stages; xl850 (after Carter). D. ChrysochromiiUna 

 parva Lackey; x3200 approx. (after L.). 



Family •/. Prymnesiidae. These flagellates have three flagella and a 

 rather plastic body. Prymyiesiiwi Massart (Fig. 4. 8, A) has a short in- 

 active median flagellum and two long ones, and usually two yellow-green 

 to brown chromatophores. Platychrysis Geitler (Fig. 4. 8, B, C) shows both 

 amoeboid and flagellate stages. The flagella of the latter resemble those of 

 Prymnesium, but are coiled and apparently inactive in the amoeboid 

 stage (31). In Chrysochromulina Lackey (174; Fig. 4. 8, D) the median 

 flagellum is longer than the other two, which are usually trailed in 

 swimming. 



