8o 
Notes on Recent Literature. 
struck with the differences which exist between individuals or 
groups of individuals. The study of these elementary species is of 
great importance, but for the purposes of a general systematic work, 
the first essential is that a true perspective should be maintained. 
The union of forms which have previously borne separate names 
into more comprehensive genera unfortunately entails some added 
complications of synonomy, and no doubt opinions will differ as to 
the merits of the changes in particular cases. 
Of the classes into which Wille divides the Chlorophyceae, the 
name Chaetophorales is applied to the group which corresponds 
generally with the old Confervoideae, excluding, however, the 
Sphaeropleaceae and Cladophoraceas, which, following later practice, 
are now placed with the Siphonocladiales. The class corresponds 
very closely with the Ulotrichales of Blackman and Tansley and of 
Oltmanns, and it was perhaps unnecessary to invent a new name, 
more especially as the divergence is much less than that which 
exists between the new Protococcales (Wille) and the groups of the 
same name of Blackman and Tansley and of Oltmanns. Following 
recent practice, the old Siphoneae have been divided into two 
groups, the Siphonales and Siphonocladiales. 
As regards the nomenclature of the orders, the new orders 
Botryococcaceae and Ophiocytiaceae necessarily follow from Wide’s 
views with regard to the Heterokontae, and perhaps the same 
applies to the order Hydrogastraceae, which is formed to receive 
Botrydium and Protosiplion, since the older name of Botrydiaceae 
has in recent years been restricted to the Heterokontous 
forms. In the Chaetophorales, the formation of the independent 
order Aphanochaetaceae is the only logical alternative to the inclusion 
of Aphanochaete and Coleochaete (Coleochastaceae) with the Chaeto- 
phoraceae. The three genera Trentepohlia, Phycopeltis and Ceplia- 
leuros form a very natural and strongly characterized group and we 
are glad to see that Wide agrees with Oltmanns in giving them rank 
as the order Chroolepidaceae. 
The general form of the PJlauzenfami lien is so familiar that no 
further comment is needed, and though we disagree with the author’s 
views as to the value of the characters of the zoospore from a 
systematic point of view, we are none the less highly appreciative 
of the care and thought which has been devoted to the revision of 
this section. 
R.P.G. 
R. Mauley, Printer, 151, Whitfield Street, Fitzroy Square, W, 
