Phylum Phaeophyta [ 63 



They are approximately of radial symmetry, the axis being shorter than the diameter. 

 The skeleton is completely imbedded in protoplasm. It may be a mere ring; or the 

 ring may bear radially projecting spines; or it may be the margin of a more or less 

 complicated basket-shaped network coaxial with the cell. Numerous brown plastids 

 lie near the surface of the protoplast. There is no cell wall. The double cells, like 

 two cells lying face to face, which have occasionally been seen, are not stages of 

 conjugation, but of cell division, in which one daughter cell retains the original 

 skeleton while the other develops a new skeleton in the position of a mirror image 

 of the original one. 



Lemmermann and Gemeinhardt accounted for only six genera and twenty-four 

 species, but Gemeinhardt recognized numerous varieties, and it is probable that the 

 number of species has been underestimated. Mesocaena, the skeleton a mere ring, 

 smooth or spiny; Dictyocha, Distephanus, Cannopilus, the skeleton more or less 

 netted. 



Family 6. Chrysamoebida [Chrysamoebidae] Poche in Arch. Prot. 30: 157 (1913). 

 Families Rhizochrysidaceae , Chrysarachniaceae, and Myxochrysidaceae Pascher in 

 Beih. Bot. Centralbl. 48, Abt. 2: 323 (1931). Family Rhizochrysididae Hollande in 

 Grasse Traite Zool. 1, fasc. 1: 547 (1952). Families Rhizochrysidae and Myxochry- 

 sidae Hall Protozoology 130, 132 (1953). Amoeboid organisms with brown plastids 

 of the form of one or two parietal films in each cell. Rhizaster, an attached organism 

 resembling Cyrtophora and Pedinella but lacking the flagellum. Chrysocrinus, at- 

 tached to algae, the protoplast covered by a dome-shaped shell punctured by many 

 pores through which project the slender psudopodia. Chrysamoeba, a freely moving 

 cell usually with one flagellum; Rhizochrysis, similar, without the flagellum. Myxo- 

 chrysis, a large multinucleate form. Chrysarachnion, the cells clustered and linked 

 together by strands of protoplasm. Lagynion, having an attached vase-shaped lorica 

 from which projects usually a single slender pseudopodium. Chrysothylakion, with 

 a retort-shaped lorica from which project many slender pseudopodia, branching 

 and anastomosing. Only the plastids distinguish these organisms from various genera 

 classified as Rhizopoda, Heliozoa, or Sarkodina. 



Family 7. Thallochrysidacea [Thallochrysidaceae] Pascher (1925). Brown or- 

 ganisms producing definite filaments of walled cells and reproducing by anteriorly 

 uniflagellate zoospores. T hall ochry sis. Phaeodermatium. 



Order 3. Vaucheriacea [Vaucheriaceae] Nageli Gatt. einzell. Alg. 40 (1849). 



Class Heterokontae and orders Chloromonadales and Confervales Luther in 

 Bihang Svensk. Vetensk.-Akad. Handl. 24, part 3, no. 13: 19 (1899). Not 

 Chloromonadina Klebs (1893); not order Confervoidea C. Agardh (1824). 



Vaucheriales Bohlin Grona Algernas 25 (1901). 



Order Vaucheriales Clements Gen. Fung. 14 (1909). 



Orders Heterochloridales, Heterocapsales, Heterococcales, Heterotrichales, and 

 H eter osiphonales Va.s.ch.tr mlitdwigizbZ: 10-21 (1912). 



Division Heterokontae, Classes Heterochloridineae, Rhizochloridineae, Hetero- 

 capsineae, Heterococcineae, Heterotrichineae , and Heterosiphoneae, and or- 

 ders Rhizochloridales and Botrydiales Pascher in Beih. bot. Centralbl. 48, 

 Abt. 2: 324 (1931). 



Class Xanthomonadina with orders Heterochloridea and Rhizo chloride a De- 

 flandre in Grasse Traite Zool. 1, fasc. 1: 212, 217, 220 (1952). 



Order Heterochlorida Hall Protozoology 133 (1953). 



