144 
Reviews. 
The Chlorophycese of Mr. West are divided into a number of 
“orders,’’ a taxonomic unit corresponding to the “Series” of 
Engler’s Syllabus. The separateness of the CEdogoniacese is so 
far recognised that they are allowed a separate “order”— 
CEdogoniales. The Chsetophorales almost correspond to the 
Ulotrichales of the “ Revision.” We prefer the latter name since 
it is taken from a more primitive type than the “hair-bearers.” 
The Ulvaceae are separated in a special “order,”the Ulvales, as in 
the “ Revision,” and the Prasiolaceae are given another—the Schizo- 
goniales,—with the remarks that “the genus Prasiola has no relation¬ 
ship to the Ulotrichaceae’’ and “Ulvales and Schizogoniales are 
parallel groups, each of which has had a separate origin from the 
Protococcoideae.” This is very likely. Bohlin is followed in assigning 
Microspora not only to a separate family, but to a separate order— 
Microsporales. The Cladophoracese, Pithophoraceae and Sphaero- 
pleaceae are placed together in the Cladophorales, which Mr. West 
refuses to unite with the Siphoneae. But a comparison of the 
cytological characters of a coenocytic segment of Chulophora with 
those of some of the Siphonocladeae, e.g. Siphonocladus itself, most 
strongly suggests that Schmitz was right in deriving the Clado¬ 
phoracese from a Valoniaceous type in which there has been a 
precocious segmentation of the coenocytic thallus. 
The Conjugatae are primarily divided in the classical way—the 
filamentous forms (Zygnemaceae) into Mesocarpeae and Zygnemeae 
(including Spirogyra). We have recently given reasons for pre¬ 
ferring, with Palla, to classify these forms according to the nature of 
their chromatophores. Mr. West is a specialist on the Desmids, and, 
as he points out, it is very interesting to note that his conclusions as to 
their classification, founded on a careful comparative study of their 
external form and its variations, coincide very closely with 
Liitkemuller’s conclusions drawn from the minute structure of their 
cell-walls. This fact gives his classification a very solid basis, and 
we must certainly accept it as most nearly representing the truth. 
With regard to the question whether the Desmids or the fila¬ 
mentous Conjugates represent more closely the ancestors of the 
group, Mr. West holds very strong views. Not only in the present 
work, but elsewhere he repeatedly states that he has “proved” that 
the Desmids are descended from filamentous Conjugates. For 
instance (p. 27), “ it has been clearly shown that the Desmidiacese 
is unquestionably a family of Conjugates derived by retrogression 
from filamentous ancestors, and therefore they cannot by any 
possible means have had a direct origin from unicellular motile 
