PAPtNFUSS: CLASSIFICATION OF THE ALGAE 133 



vegetative organization; and he suspects that, if tlie fossil record were known, 

 all transitions to the green algae would be found. It is quite probable that the 

 Charophyceae evolved from the Chlorophyceae. But this is probably true also of 

 other green plants above the level of the algae and, if all the intermediate types 

 had persisted or were known from fossils, it would be impossible to separate the 

 angiosperms from the green algae. The presence in the Charophyceae of green 

 plastids, their storage of starch, and the fact that they are haploid can hardly be 

 considered valid criteria for retaining them among the Chlorophyceae. 



The classification below is adapted from the systems of Pia (1927), Peck 

 (1946), andMadler (1953). 



Phylum CHAROPHYCOPHYTA Papenfuss (1946, p. 218) 

 Syn.: Charophyta Migula (1890, p. 60) 



Class Charophyceae G. M. Smith (1938, p. 127) 



Order CHARALES Llndley (1836, p. 414, as "alliance") 



Syn.: Sycidiales Miidler (1952, p. 14); Trochiliscales Madler (1952, p. 14) 

 Family Palaeocharaceae Pia (1927, p. 90) 

 Family Characeae Richard ex C. Agardh (1824, p. xxvii) 



Syn.: Lagynophoraceae Stache (1880, not seen, cited from Madler, 1953) 

 Family Clavatoraceae Pia (1927, p. 91) 



Family Trochiliscaceae Karpinski orth. mut. Peck (1934, p. 104) 

 Family Sycidiaceae Karpinski orth. mut. Peck (1934, p. 116) 



Phylum Euglenophycophyta 



Characterization: This phylum comprises both green and colorless, naked, and often 

 spirally twisted unicellular, flagellated, or rarely palmelloid organisms with a complex 

 vacuolar system. In some forms (certain species of Euglena) the periplast is soft and 

 the individuals thus show marked metaboly; in others (Pfiacus) it is rigid and the cells 

 consequently do not change in shape. Depending upon the genus, the individuals usually 

 possess one or two or occasionally three flagella that arise from the invaginated anterior 

 end of the cell, the reservoir. The available information on the structure of the flagella 

 of members of this phylum has been summarized by Vlk (1938), Brown (1945), Pitelka 

 (1949), Pringsheim and Hovasse (1950), and Jahn (1951). The flagella are apparently 

 provided with a single row of cilia along their entire length (but see the review by Pring- 

 sheim and Hovasse, 1950). Certain of the colorless forms, the Peranemaceae, are equipped 

 for the ingestion of particulate food as contrasted with the green and saprophytic species, 

 which apparently are unable to ingest solid food. In the green species the pigment 

 complex consists of chlorophyll a, chlorophyll b, beta-carotene, and several unidentified 

 xanthophylls (Strain, 1951, p. 253). Typically, food is stored in the form of the polysac- 

 charide paramylum. No coccoid or filamentous types have become known in this phylum. 

 The ordinary method of reproduction is by cell division. In some forms cysts are formed, 

 the contents of which divide into a number of cells. Various instances of gametic union 

 have been reported but none of these is entirely convincing. 



History: The early history of the classification of the euglenids is inextricably 

 linked with that of many other groups of microorganisms, or Infusoria as they 

 were named by Ledermueller in 1763 (according to Kent, 1880-1881, p. 14). 

 Hence, in reviewing the classification of the euglenids the history of the entire 

 complex must be taken into account and the steps traced that led finally to their 

 separation as an autonomous phylum. 



Although a few representatives of the Euglenophycophyta had already been 

 described before the end of the eighteenth century, especially by 0. F. Miiller 

 (1786) in his Animalcula infusoria . . .(the first comprehensive work on the 

 Infusoria), it was Ehrenberg who in 1838 in his volume Die Infusionsthier- 



