246 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
articulations. The sterigmata are very closely aggregated, and hence indis- 
tinct en masse. 
Specimen 18.—Var. albinea, Ach. (Syn. Parmelia erosa, Borr.); Falmouth and 
Cornwall, Miss Warren. The spermogones are distinct, black, sub-prominent 
papillae, generally isolated; the spermatia are jth long, and sth broad, and 
the sterigmata about ath long, consisting of a very few longish, cylindrical, and 
generally irregular articulations. British North America, Ricuarpson; Rocky 
Mountains, Drummonp: on the trunks of trees, Troy, U. 8.; on Gleditschia, Ohio, 
U.S., Lea: Swan River, Australia, Jas. DRuMMoND; on stone walls, Boston, U.S., 
F. Boorr. All these specimens are in Herb. Hooker, Kew, and all possess both 
apothecia and spermogones. 
Speciges 6. P. astroidea, Fr., 
Which occurs in Europe and America. This, as well as the following species, seem 
to me mere varieties of P. séel/aris; this is characterized by the very soderiifer- 
ous surface of the thallus. The spermogones are externally similar to those of 
P. stellaris ; but the spermatia are usually larger, and the sterigmata composed 
of much longer, delicate, linear cells or articulations. The spermatia, in one 
specimen, in Herb. Botanical Society of Edinburgh,—the habitat not being given, 
—are znth long. The plant is associated with var. tenella of P. stellaris. 
’ 
Species 7. P. cesia, Fr., 
A native alike of Northern America and of Europe. It is chiefly saxicolous, cha- — 
racterized by plentiful, roundish, gray soredia on the very narrow convex lacinie. 
Its spermogones are essentially those of P. stellaris ; they would appear to have 
been described by SPRENGEL as Hndocarpon athallum. 
Specimen 1.—On boulders and walls, roadside between Sligachan and Portree, 
Skye, August 1856, W. L. L. The plant is associated with var. tenella of 
P. stellaris ; and, indeed, P. cwsia, P. stellaris, and P. astroidea, graduate into each 
other, and are certainly, in my opinion, referrible to a common type. The sper- — 
matia are very small, about sath to zath long; the sterigmata very delicate, 
irregular, and composed of short, roundish articulations. 
Specimen 2.—ScHARER exs. 348, (sub. Parmelia pulchella, 2 dubia) ; on palings © 
about Belp. There are no apothecia; the spermogones are, in all respects, those 
of P. stellar is. 
SPECIES 8. P. conjluens, Fr.,’ 
A foreign species, growing in equatorial America, ‘Aces and Asia. 
Specimen 1.—New Orleans; on bark, Drummonp; in Herb. Hooker, Kem 
(sub nom. Lecanora atra). The apothecia closely resemble those of Z. atra ; but 

