246 Prof. Dr. 0. Mcreschkovsky's Diagnoses 



XXVI. — Diagnoses of some Lichens. 

 By Prof. Dr. C Mereschkovsky. 



During the last ten years I have described, in various publi- 

 cations, quite a number of new lichens. As, with a few 

 exceptions, I did not conform with tiie international con- 

 vention requiring a Latin diagnosis, I have considered it 

 desirable to add here to my previous descriptions in Russian 

 or French short Latin diagnoses for the greater number of 

 new forms. 



All my collections and notes having been left in Russia, I 

 regret that in some cases the diagnoses are not so complete as 

 they might be. 



Usneaflorida, var. divaricata, Mer. 

 Mereschkovsky, Adclit. Lichenogr. Eoss. i., Oest. Bot. Zeitschr. 1921. 



Thallus mediocris, circiter 7-8 centim. longus, erectus, ramis divari- 

 catis, fibrillis riuraerosis ut in Usnea harhata typica munitis. 



Spec. orig. (numero?.) * in herb, nieo Kazani. 

 Rossia Media, Esthlandia. 



Usnea hirta, forma minutissima, Mer. 



Mereschkovsky, Beitr. z. Kenutn. Flecht. ReTal, Kazan, 1909, p. 10 ; 

 id. Lich. Rossiae exsicc. no. 53. 



Thallus minutus, 2-3 centim. baud superans, pulvinulas baud 

 formans, parce sorediatus vel imdus, semper sterilis. 



S'pee. orig. (numeros.) in herb, meo Kazani. 

 Rossia Media, Fennia, Tauria. Etiam in Gallia! et 

 Helvetia! 



Usnea plicata, forma vtigans, Mer. 

 Mereschkovsky, Beitr. z. Keuntn. Flecht. Reval, Kazan, 1909. 

 Thallus elongatus, subscabrosus, liberus, substrato baud affixus. 



Spec. orig. in herb, meo Kazani. 



The absence of any trace of damage shows that they are 

 not simply fragments torn off from normal specimens. 

 Esthland ; Reval, living on trunks of Pinus. 



* " (numeros.) " means at least twenty good, identified specimens ; 

 " (numerosiisim,)" about one hundred specimens. 



