Phylum Pyrrhophyta [ 95 



zinc chlor-iodide. The euglenids store granules of a white solid believed not to be 

 starch and called paramylum. 



The plastids of cryptomonads and dinoflagellates are of various colors, oflF-color 

 green, yellow, brown, bluish, or red. Those of dinoflagellates contain chlorophylls 

 a and e; the latter is an exceptional chlorophyll which occurs also in Tribonema. 

 Euglenids and chloromonads are typically of the same bright green color as typical 

 plants, and the euglenids are known to have the same chlorophylls, a and b, as 

 typical plants (Strain, in Franck and Loomis, 1949). 



The groups here brought together exhibit family resemblances in details of the 

 mitotic process, so far as these are known. The nuclear membrane usually persists 

 through the process. In many examples the chromosomes appear to be present at all 

 times, and are quite numerous, elongate, and of the appearance of strings of beads. 

 In mitosis, quite as one would assume, they divide lengthwise; the point had been 

 disputed, and was established by Hall (1923, 1925, 1937) and Hall and Powell 

 (1928). There is a neuromotor apparatus consisting of a centrosome at or near the 

 nuclear membrane together with one or more rhizoplasts connecting it to as many 

 blepharoplasts at the bases of the flagella. No spindle has been seen, unless the 

 peculiar structure, seen in Noctiluca outside of and next to the dividing nucleus, is 

 such. The centrosomes may lie at the sides of the dividing nucleus instead of at its 

 ends. In the euglenids and some dinoflagellates the nucleus contains a nucleolus-like 

 body which does not disappear during mitosis, but divides as the chromosomes do. 



There are few reports of sexual processes in this group. 



Pascher (1914) united the crytomonads and dinoflagellates in a group which 

 he named Pyrrhophyta. He and those who follow him leave the euglenids as an iso- 

 lated group. Tilden (1933) placed the four groups of flagellates with which we are 

 here concerned in division Chrysophyceae, while leaving the Phaeophyceae as a 

 distinct division. Her arrangement does not appear to be contrary to nature: the 

 cryptomonads are apparently not very far removed from the chrysomonads. The 

 different arrangement here maintained, by which the brown algae instead of the 

 cryptomonads and so forth are placed in the same phylum with the chrysomonads, is 

 believed to have the advantage that that phylum as least is well marked by char- 

 acter. 



Chadefaud (1936) proposed a group consisting of the four groups of flagellates 

 here under consideration together with the Infusoria: this on the ground that the 

 Infusoria also have deeply indented cells containing trichocysts. He did not give 

 to his proposed group a place in the taxonomic system by assigning it to a category 

 and giving it a Latin name: he called it by the French common names protistes 

 trichocystiferes and progastreades. He suggested two ideas: that if a cell marked 

 by a considerable indentation should become divided into many cells forming two 

 layers, respectively superficial and against the indentation, the resulting structure 

 would be a gastrula; and that the gastrula, and, in fact, the kingdom of animals, 

 might have come into existence in this fashion. Perhaps because of novelty, these 

 ideas seem far-fetched. So far as it concerns flagellates, Chadefaud's grouping appears 

 sound and has been followed in giving limits to the present phylum. 



The phylum is treated as a single class. 



Class MASTSGOPHORA (Diesing) Bu'tschli 



Classes Cryptomonadineae , Rhizocryptineae, Cryptocapsineae, Cryptococcineae, 

 Desmomonadineae, Desmocapsineae, Dinoflagellatae, Rhizodininae, Dinocap- 



