Phylum Pyrrhophyta [ 99 



Division Desmokontae; classes Desmomonadineae and Desmocapsineae; and 

 orders Desmomonadales, Prorocentrales, and Desmocapsales Pascher in Beih. 

 bot. Centralbl. 48, Abt. 2: 325 (1931). 

 Suborder Prorocentrina Hall Protozoology 142 (1953). 

 Solitary cells, mostly flagellate in the vegetative condition, the flagellate stages 

 either naked or bearing a close wall of two valves, with two flagella at the anterior 

 end, one extending forward while the other is bent circumferentially and causes the 

 cell to whirl while swimming. 



The few known organisms of this group may be treated as a single family. 

 Family Adinida Bergh in Morph. Jahrb. 7: 273 (1882). Family Prorocentrinen 

 Stein Org. Inf. 3, II Halfte: 8 (1883). Family Prorocentrina Butschli in Bronn Kl. 

 u. Ord. Thierreichs 1: 1002 (1885). Family Prorocentraceae Schiitt in Engler and 

 Prantl Nat. Pflanzenfam. I Teil, Abt. lb: 6 (1896). Prorocentridae Kofoid in Bull. 

 Mas. Comp. Zool. Harvard 50: 164 (1907). Family Prorocentridae Poche in Arch. 

 Prot. 30: 160 (1913). Desmocapsa, Haplodiniuni, Desmomastix, Pleuromonas, 

 Exuviaella, Prorocentrum; minute brown organisms, mostly marine. 



Order 3. CystoflageUata (Haeckel) Butschli in Bronn Kl. u. Ord. Thierreichs 



1, Abt. 2, Inhalt (1887). 



Tribe [group of families] Gymnodinioidae Poche in Arch. Prot. 30: 161 (1913). 



Classes Rhizodininae, Dinocapsineae, Dinococcineae, and Dinotrichineae; orders 



Gymnodiniales, Rhizodiniales, Dinocapsales, Dinococcales, and Dinotrichales 



Pascher in Beih. bot. Centralbl. 48, Abt. 2 : 326 ( 193 1 ) . 



Suborders Gymnodinina, Dinocapsina, and Dinococcina Hall Protozoology 143, 



147, 149 (1953). 



Haeckel ( 1866) made of Noctiluca alone a phylum under the name of Noctilucae. 



He had the carelessness, as it appears, to publish in the same work the synonymous 



phylar name Myxocystoda as a label in a phylogenetic diagram. In 1873 he used a 



third name, CystoflageUata, and Biitschli took this up; in the text of the Klassen 



und Ordnungen ambiguously as an Unterabtheilung or Ordnung, in the table of 



contents definitely as an order. Allman (1872) had shown that Noctiluca belongs to 



the present group. Biitschli did not agree with this opinion, but it is evidently correct, 



and Haeckel's name becomes the valid one for the order to which Noctiluca belongs 



Typical members of the present order are naked motile cells with brown plastids. 



The two flagella are attached near the equator of the cell. One of them extends in a 



posterior direction, in a groove called the sulcus. The other extends horizontally about 



the cell (generally to the right, in the reversed image seen in the microscope), lying 



in a groove called the girdle. The part of the cell anterior to the girdle is called the 



epicone, the part posterior to it, the hypocone. From the typical structure as thus 



described, there are, as will be seen, many deviations. 



The species, of which more than three hundred are known, may be treated as nine 

 families. 



1. Relatively unspecialized; having stages freely 

 propelled by two flagella, with a single girdle, 

 no tentacles, and unspecialized eyespots or 

 none; not parasitic; commonly pigmented. 



2. Walled and non-motile in the vegeta- 

 tive condition Family 1. Phytodiniacea. 



2. Flagellate in the vegetative condition Family 2. Gymnodiniacea. 



