1903] Collins,— Ulothricaceae and Chaetophoraceae 73 
of Stigeoclonium. In a footnote Hormiscia Fries is proposed in 
place of Urospora Areschoug, but the genus is removed from the 
scope of the present paper. If we accept the author’s principles, we 
cannot escape from the last two changes; as regards the first, the 
vital question is, what is the Conferva of Linnaeus? This can only 
be settled by the original specimens; if any are in existence, the 
examination should be made at once; if none are to be found, or if, 
as is rather likely, their condition is such as to render certainty in 
the matter impossible, it would hardly seem expedient to discard Coz- 
Jerva, as it is now used with a quite definite extension by practically 
all algologists. 
This question of the actual type specimens is the one which may, 
if any, seriously affect Dr. Hazen's conclusions, in other partic- 
ulars than the Conferva question. Until the test is actually made, 
no one can say whether we can reach any certain conclusions from 
specimens often over a century old, when even comparatively modern 
dried specimens are often of doubtful value; but until we either know, 
or are sure that we cannot know what the type was, is it not better 
to take the more conservative course, and make as few changes as 
possible? The burden of proof certainly rests on the one proposing 
the change. 
Apart from the question just considered, there is little but praise 
to give the work. Descriptions and plates are clear, localities are 
given with dates and with collectors’ or exsiccatae numbers. The 
work is of special interest to New England botanists, as of the 56 
species recognized, 1o of them being new, 44 are represented at New 
England stations. ‘Two forms and two varieties are recognized, the 
distinction being clearly made between form and variety; there are 
notes on 28 rejected or doubtful species and varieties. 
The reviewer feels a real satisfaction, in which he is sure others 
will join, that when these hitherto perplexing and exasperating plants 
appear in the early spring of 1903, we shall be in a very different posi- 
tion in regard to them from the one we have heretofore occupied. — 
F. S. COLLINS. 
