Phylum Phaeophyta [ 61 



tous, reproducing by zoospores bearing paired unequal flagella. Nematochrysis, the 

 filaments unbranched; Phaeothamnio7i, the filaments branched. These organisms are 

 believed to represent the transition between the Chrysocapsacea and the typical 

 brown algae. 



There is a family Amphimonadidae or Amphimonadaceae of unwalled colorless 

 flagellates with paired supposedly equal flagella. They appear to belong to the 

 kingdom of plants, in the neighborhood of Chlamydomonas and Polytoma. If, how- 

 ever, future study shows their flagella actually to be respectively pantoneme and 

 acroneme, they are to be placed in the present order. 



Order 2. Silicoflagellata Borgert in Zeit. wiss. Zool. 51: 661 (1891). 

 Chromomonadina Klebs in Zeit. wiss. Zool. 55: 394 (1893). 

 Order Chromomonadina Blochmann Mikr. Tierwelt ed. 2. Abt. I: 57 (1895). 

 Subclass Chrysomonadineae Engler in Engler and Prantl Nat. Pflanzenfam. 



ITeil, Abt.'la: iv (1900). 

 Order Chrysomonadales Engler Syllab. ed. 3: 7 (1903). 



Chrysomonadinae; Euchrysomonadinae , with order Chromulinales; Chryso- 

 capsinae; and Rhizochrysidinae Pascher in Siisswasserfl. Deutschland Heft 2 

 (1913). 

 Chrysomonadales, Chrysocapsales, Chrysosphaerales, and Chrysotrichales Pas- 

 cher in Ber. deutschen bot. Gess. 32: 158 (1914). 

 Order Chrysomonadina Doflein Lehrb. Prot. ed. 4: 401 (1916). 

 Order Chrysomonadida Calkins Biol. Prot. 258 (1926). 



Classes Chrysomonadineae , Rhizochrysidineae, Chrysocapsineae, Chrysosphaeri- 

 neae, and Chrysotrichineae Pascher in Beih. bot. Centralbl. 48, Abt. 2: 323 

 (1931). 

 Suborders Euchrysomonadina, Silicoflagellina, Rhizochrysidina, and Chrysocap- 

 sina Hall Protozoology 125, 128, 130, 132 (1953). 

 Organisms of much the character of Ochromonadalea, but producing flagellate 

 stages with a single flagellum, or not producing flagellate stages. The detailed 

 structure of the flagella has seemingly never been determined. Statospores are known 

 to be produced by Chromulina, Mallonionas, and (of somewhat exceptional charac- 

 ter) by Hy drums. Sexual reproduction has not been observed. Mitosis, with an 

 intranuclear spindle and numerous chromosomes, was observed by Doflein (1916) 

 in Rhizochrysis. 



This order is supposed to represent the direct ancestry of orders Choanoflagellata 

 and Hyphochytrialea. 



1. Neither amoeboid nor truly filamentous. 

 2. Not flagellate in the vegetative condi- 

 tion. 



3. Microscopic colonies Family 1. Chrysosphaeracea. 



3. Macroscopic gelatinous colonies 



simulating filaments Family 2. Hydruragea. 



2. Flagellate in the vegetative condition. 

 3. Without prominent siliceous struc- 

 tures Family 3. Chrysomonadina. 



3. With siliceous scales usually bearing 



bristles Family 4. Mallomonadinea. 



3. With siliceous internal skeletons Family 5. Actiniscea. 



