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OHIGINAL COMMUNICATIONS. 
On the Structure of Lecidea lugubris (Sommf.) 
By W. Lauder Lindsay^ M.D._, Perth. 
While engaged in lichenological studies in the Braemar 
Highlands during the summer of 1856 (August)^ I met with 
a beautiful little lichen, which has not hitherto, I believe, 
been detected in Britain, and which appears also to be 
very rare on the continent of Europe. It was the Lecidea 
lugubris of Sommerfeldt Suppl. Lapp.,^ 143, and Schserer's 
^Enumeratio Critica Lichenum Europseorum,^ Bern, 1850, 
p. 101) ; and the Sch(jereria lugubris of Korber [' Systema 
Lichenum Germanise,^ Breslau, 1856, p. 232). I was fur- 
ther fortunate enough to find specimens bearing not only 
apothecia, but spermogones; the latter organs not having 
apparently been hitherto discovered or described. The 
structure of the apothecia is exceedingly beautiful ; and the 
peculiar spores serve to distinguish this species from all 
other British Lecidese. The facts that the structure of this 
lichen is probably, in great measure, unknown to British 
lichenologists ; that the plant has not hitherto been found in 
Britain, while it is a rare alpine continental species ; that 
its spermogones have not been heretofore, so far as I am 
aware, discovered or described ; and that its spores serve to 
distinguish it from all other British Lecidese — induce me to 
offer the following account of its external characters and 
minute anatomy, based on my examinations of specimens 
collected at Braemar. 
The Lecidea lugubris, Sommf., is placed, and very properly 
I think, by Schserer {' Enum.,^ 1. c.) in the section Psora of 
the genus Lecidea, — this section being characterised by the 
possession of a squamulose thallus; and in the subsection 
thereof in which the squamules are often aggregated or 
crowded into a plicate or areolate crust. Its external cha- 
racters place it in near affinity to the more familiar Lecidea 
coeruleo -nigricans, Sch. (Schaer., ''Enum.,^ 101, Lich. Helvet. 
exsicc, 168). It also bears a resemblance, in some particu- 
lars, to L. decipiens, Ach. (Schaer., ^ Enum.,^ 95, L. H. E., 164, 
and plate v, fig. 2 ; Biatora decipiens, Ehrh., Hepp, ' Die 
Elechten Europas,^ 1853, 120; Tulasne, Mem. pour servir 
^ rhistoire organographique et physiologique des Lichens, 
VOL. V. Q 
