10 
THE JOUltN ATj OF BOTANT 
overwhelmingly American, and that while six genera are represented 
among the American species illustrated, Pteris (in the usual sense) 
has almost a majority,—six species. The claims of these six species 
as typical are about equal. Here, again, historical usage may pro¬ 
perly be considered and a free-veined species selected, since the netted- 
veined species are commonly placed in separated sections under 
distinctive names. P. longifolict is a reasonable selection, and this is, 
in fact, the type indicated by Christensen in the Index Filicum. 
An examination of the Linnean literature thus shows that Pteris 
of Linnaeus can be typified by P. aquilina only by recourse to a rule 
that an oldest known or indigenous species must be selected as type. 
In the present instance this would result in excluding from considera¬ 
tion the largest numerical element of the originally included species, 
namely P. longifolict and allied species, known as Pteris for more 
than a century. There appears to be no warrant for this, other than 
the mandatory provision of a rule whose basic idea is essentially 
sound. To such a course the liberal spirit of the new Type-basis Code 
is directly opposed. 
But assuming that the claims of the name Pteris to use in its 
traditional sense could not be clearly shown, it is still almost certain 
that it would never be replaced in common usage; nor, in the writer’s 
opinion, should it ever be displaced. Under the type-basis or any 
other code or set of rules, it is evident, many important genera can 
retain their usual names only by special exception, and there need be 
no more than passing regret over the necessity for a list of nomina 
conservanda. The principle of “ saved ” names is logically correct, 
and is quite defensible on grounds of expediency alone. Such a list, 
to receive general support, must naturally he subject to revision and 
be restricted to those genera that, because of their economic importance, 
numerous species, or involved nomenclatural history, have legitimate 
claims to being taken up under their best known names. If properly 
compiled, with a brief analysis of each case, a carefully considered 
list would do away with a vast amount of detailed discussion aimed at 
saving wellknown generic names “ by rule,” and would make appre¬ 
ciably easier the study of plants themselves. In spite of harsh judge¬ 
ments often levelled at systematic botanists, this, rather than the 
shuffling of names, is still their chief concern. 
Smithsonian Institution, Washington, D.C. 
Dll. STIRTON’S NEW BRITISH MOSSES REVISED. 
By H. N. Dixon, M.A., F.L.S. 
The late Dr. James Stirton from time to time published papers, 
ranging from 1870 to 1915, dealing with British mosses, in the course 
of which he described numerous new species, reaching the considerable 
number of over 110; that is to say, an addition of nearly 20 per cent, 
to the usually recognized total of British mosses. During Dr. Stirton’s 
lifetime very little opportunity was offered for examining these species, 
but since his death his herbarium of mosses has come into the posses¬ 
sion of the British Museum (Nat. Hist.), and it has been possible to 
