1920] Seichellr-Gardner : ChIoi-ophycca>e 143 



Order 1. PROTOCOCCALES (meneghixi) oltmaxns 



Unicellular isokontae, motilo or nonmotile, often occurring singly 

 or in larger or smaller, definite oi- indefinite eoloiiies or eoenobia, or 

 even simple coenocytes, often provided witli mucilaginous teguments 

 of more or less ample dimensions and of various shapes, never properly 

 multicellular; number and shape of chromatophores (chloroplasts) 

 various; pyrenoids often present: i"('i)i'oductivf methods various as 

 outlined for the series Isokontae. 



Prolococcalfs Oltmanns, Morph. und Biol, der Algen, vol. 1, 1904, 

 p. 169; West, Algae, vol. 1, 1916, p. 160. Protococcoideac Meneghini, 

 Cenni sulla organ, e. fisiol. delle Alghe, 1838, p. 4 (of reprint) ; Black- 

 man and Tansley, Revis, Class. Green Algae, 1902, p. 21 ; Wille, in 

 Engler and Prautl, Natiirl. Pflanzenfam., Nachtr. zum 1 Th., 2 Al)t., 

 1909, p. 3. 



The Protococcales, or Protococcoideae as they have long been 

 designated, form a rather large and seemingly heterogeneous order. 

 They are mostly iniiabitants of the fresh waters and, although unicel- 

 lular in the broad sense, are varied in their form, aggregation and 

 methods of reproduction. Our marine species are few so far as 

 known, hut undou])tedly a considerable number yet I'emain to be 

 detected. This is i)articularly true of the endophytic species of our 

 coast whose presence and development are very little understood at 

 present. 



Key to the Families 



1. Thallus of larger or smaller colonies (or aggregations of cells) 



1. Palmellaceae (p. 143) 



1. ThaUus strictly unicellular 2. Chlorochytriaceae (p. 146) 



FAMILY 1, PALMELLACEAE (decaisne) naegeli 



Cells united into larger or smaller colonies by mueihiginous modi- 

 fication of the outer walls, usually provided with a single parietal 

 chromatophore (chloroplast) containing a single pyrenoid ; repro- 

 duction by bieiliated zoospores or by isoplanogametes; fragmentation 

 of colonies often takes place. 



Palmellaceae Naegeli, Die neuern Algensyst., 1847, p. 123; West, 

 Algae, vol. 1, 191 (i, p. is:!. Palmelleae Decaisne, Essai snr nne classe 

 des Algues, etc., 1842, p. 327. 



