EXPLANATION OF PLATES* 
ILLUSTRATIVE OF DR LAUDER LINDSAY’S MEMOIR ON THE SPERMOGONES AND 
PYCNIDES OF LICHENS. 

Prate LV. 
Illustrative of the genera Usnua, Hoffm.; Nevurorocon, Nees and Flot.; Axecrorra, Ach., Nyl. ; 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
and Cutorga, Nyl. 
. Usnea barbata, Fr., var. plicata, Fr., from California ; showing the long pendulous ramules 
covered over with spermogonal warts. 
. Spermogones from the same specimen, more highly magnified, 
. U. barbata, Fr., from Tasmania; showing spermogonal warts covering the cilia, which 
radiate from the margins of the apothecium. 
. U. barbata, Fr., var. hirta, Fr., from Rio Janeiro, Portion of thallus profusely covered 
with small spermogonal warts, most of which have black-punctate ostioles. 
5. Spermogonal warts from the same specimen, more highly magnified. 
. U.barbata, Fr. Section of a spermogone, showing the ostiole a; the multiple or compound 
cavity b, dividimg into numerous anfractuosities, or compartments with sinuous walls ; 
ce, the gonidic layer of the thallus; d, the white medullary tissue, composed of delicate 
branching tubes; e, the cortical layer of the thallus, consisting of closely aggregated 
irregular cells. 
. U. barbata, Fr. Sterigmata a, and spermatia b, Elongated, branching, delicate filaments, 
which project from among the spermatiferous sterigmata, c (in right-hand figure). 
. Sterigmata and spermatia of the same species, from a Tasmanian specimen. ‘The letters 
a, b, have the same reference as in fig. 7. 
Neuropogon melaxanthus, Ach. a, The black fusiform tips of the ramuscles, the seat of 
the compound or confluent spermogones. 
Portion of one of the spermogoniferous ramuscles more highly magnified. 
. Sterigmata and spermatia of NV. melaxanthus ; specimen from Hermite Island, Cape Horn ; 
a, sterigmata ; b, spermatia. 
. Alectoria Taylort, Hook., from Kerguelen’s Land: a, apothecium; 6b, Lecidea alectorie 
mihi, dotted over the under surface of the apothecium, and over the surface of the thallus. 
. A, Taylori, showing the tips of the ramuscles, black and warted from the presence of the 
spermogones 6; a, an apothecium, young ; c, apothecia immersed, punctiform, and black, 
of Lecidea alectorie mihi. 
* The microscopical analyses were chiefly made with the combination of powers of Nachet’s microscope (Petit 
modéle of 1851), which magnify 380 diameters. 
The following is the scale of ;5,th of an inch, to a the sterigmata, spermatia, and stylospores are drawn :— 
| 1000 
The fragments of thallus bearing spermogones or pycnides are mostly magnified more or less, in order that these 
organs may be the more easily recognised. The sections of spermogones, which are mostly diagrammatic, are also 
variously magnified. 
VOL. XXII. PART I. 4c 
