Phylum Phaeophyta [ 55 



and distinguished these fungi from practically all others by the presence of cellulose 

 in their walls. 



The phylum thus assembled may be organized as four classes. 

 1. Miscellaneous groups, mostly small and rela- 

 atively unspecialized, of varied body type; not 



of the characters of the following groups Class 1. Heterokonta. 



1. Comparatively numerous and specialized 

 groups. 



2. Unicellular brown organisms with shells 



of silica consisting of two parts Class 2. Bacillariacea. 



2. Organisms of fungal or chytrid body 

 types producing swimming spores with 



paired unlike fiagella Class 3. Oomycetes. 



2. Filamentous and thallose brown algae Class 4. Melanophycea. 



Class 1 . HETEROKONTA Luther 



Class Flagellata or Mastigophora Auctt., in part. 



Class Heterokontae Luther in Bihang Svensk. Vetensk.-Akad. Handl. 24, part 



3, no. 13: 19 (1899). 

 Subclass Chrysomonadineae Engler in Engler and Prantl Nat. Pflanzenfam. I Teil, 



Abt. la: iv (1900). 

 Class Silicoflagellatae (Borgert) Lemmermann in Ber. deutschen bot. Gess. 19: 



254 (1901). 

 Phylum Siphonophyceae and class Vaucherioideae Bessey in Univ. Nebraska 



Studies?: 285, 286 (1907). 

 Chrysophyceae and Heterokontae Pascher in Ber. deutschen bot. Gess. 32: 158 



(1914). 

 Divisions Chrysophyceae and Heterokontae, and classes Chrysomonadineae , Rhizo- 



chrysidineae, Chrysocapsineae, Chrysosphaerineae, Chrysotrichineae, Hetero- 



chloridineae, Rhizochloridineae, Heterocapsineae, Heterococcineae, Hetero- 



trichineae, and Heterosiphoneae Pascher in Beih. bot. Centralbl. 42, Abt. 2: 



323,324 (1931). 

 Classes Ebriaceae, Silico flagellata, and Coccolithophoridae Deflandre, and Chrys- 



omonarfina Hollande in Grasse Traite Zool. 1, fasc. 1: 407,425,438, 471 (1952). 

 Class Phytomastigophorea Hall Protozoology 117 (1953), in part. 

 Phaeophyta which lack the distinctive characters of the remaining three classes. 

 Luther named the group on the occasion of his discovery of Chlorosaccus, and this 

 genus may be regarded as the type. 



The chrysomonad flagellates are the core of this class and of the first two among 

 the five orders into which it is divided. In the classification of these two orders, three 

 novelties will be noted. 



(a) Pascher (1913) made of the chrysomonad flagellates three orders character- 

 ized respectively by paired unequal flageila, paired equal flagella, and solitary 

 fiagella. Petersen (1929) found that the supposedly equal fiagella of Synura are 

 actually unlike, being respectively pantoneme and acroneme. Here, accordingly, 

 Pascher's first two orders are combined. 



(b) Pascher made separate classes or orders of groups related to the chrysomonad 

 flagellates but of distinct body type, as palmelloid, chlorococcoid, filamentous, or 



