42 REVUE BRYOLOGIQUE 



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differt foliis plerumque latioribus, suborbiculari-ovatis, 

 cellulis parietibus minus incrassatis/ nervo in pilum 

 hyalinum elongatum excurrente, foliisque perichcelialibus 



excurrentinervis. 



«... M. Muller considere cette forme comme une esp6ce 

 distincte et nous I'avions nous-memes separee d'abord du 

 B, argenieum sousle nom de B. chionocladum ; mais nous 

 avons reconnu ensuite qu'elie se relie par des transitions 

 au B. argenteum. Nous ajouterons qu'il nous semble pro- 

 bable que beaucoup des especes du groupe Argyrohrijum 

 ne sont que des races locales ou regionaies du /i. argen- 

 ieum, » • 



M. Cardot has kindly sent me a specimen of this var. 

 costaricense^ and after comparing it with numerous speci- 

 mens ot the var. lanahmi^ I am compelled tothinlc that the 

 two are not distinct. In the var. costariceiise^ I do not find 

 the leaves more « suborbicular-ovate » than is otten the 

 case with those of the var. lanalwn^ and the hyaline point- 

 ed leaf-apex, formed of the excurrent nerve, is identical 

 in the two forziis. . 



These excurrent-nerved varieties of B. argtntcum are 

 interesting for another reason. 



Brgum argyrolrkhum C. Miill. is considered by most 

 bryologistsas a distinct species. 



Mitten, however, in his Mosses of Ceylon (Journ. Linn. 

 Soc. (Bot ) XXII. p. 307, i887) placed argyrotrichuni as a 

 variety under U. argenleiun^ with the following observa- 

 tion : c( At first sight this difl'ers greatly from the common 

 states of the species as seen in Europe, but the differences 

 seem completely connected by specimens from the Nilgiri 

 Mts., and in one from Abyssinia both states of the foliage 

 are observable on the same specimen. )) 



I am strongly in favour ot this treatment of B. argyro- 

 trichutn as a var. of /?. argenieum ; there are in the Kew 

 Herbarium many Indian specimens which show, I think, 

 clearly the connection oi B. argyrotrichum \\'ii\i the var, 

 lanatum oiB. argenieum. In fact, just as we find nume- 

 rous intermediates between /?, argenieum and the var. 

 lanatum (in which I include var. costaricens€)y so also we 

 find just as many links between lanatum nnd argyro- 

 trichum. 



I send this note in the hope that bryologists will examine 

 their specimens of B, argenieum ^ var. lanatum^ and 

 report on the nerve-structure found. 



Charlton House, Kew, Surrey (England). 



Ernest S. Salmon. 



