208 



Tetrasporineae- 



The genera are : Cha&topeltis Berth old, 1878 [inclus. Myxoch&te Bohlin, 1894] ; 

 Chsetosphan-idium Klebahn, 1892 ; Dicoleon Klebahn, 1893 ; Conochsete Klebahn, 1893 ; 

 Diploch&te Collins, 1901 ; Polyckxtophom W. & G. S. West, 1903 : Oligochsetophora 

 C4. S. West, 1911. Nordstedtia Borzi (1892) is a doubtful genus. 



Some of the above genera have been regarded by various authors as reduced forms of 

 the Ulotrichales. Their habit as colonial unicells and their methods of multiplication do 

 not, however, lend much support to the view that they have originated from filamentous 



Fig. 136. A and B, Ch&tospli&ridium Pringsheimii Klebahn. C, Ch. Prinflshcimii var. 

 deprcssum G. S. West. D, a form of Coiiuchsete comusa Klebahn. ch, chloroplast ; o, oil- 

 globule. EI, Oligochaetophorn simplex G. S. West ; 1, cell stained to show nucleus () 

 and starch-grains (s). A D, x 430 ; EI, x 330. 



forms. On the other hand, the sheathed bristle such as occurs in Ch&tosphseridium, 

 Conockee.te and Dicoleon is known elsewhere only in Coleochaste, the highest type of the 

 Ulotrichales ; and the curious unattached zoosporic forms of Coleochscte recently described 

 by Lambert ('10 B), in which the thallus is reduced to a few irregularly grouped cells, 

 might be said to throw light on the possible origin of the above-mentioned genera. There 

 is, however, no evidence to show that the sheathed bristle is of any phylogenetic importance, 

 and unsheathed 1 .ristles have certainly been developed independently in several groups of 



