352 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
niothecium* or other parasitic lichenicolous fungi, or the spores of Torula lichenicola. 
They are frequently, in this isolated form, 0003" to 0006" long and :0003" broad. The 
colour of the paraphyses is generally limited to the terminal cell or a portion thereof; 
and this limitation is a peculiarity among lichens, the colour in paraphyses generally 
extending some way down the filaments and gradually disappearing. There is great 
irregularity in the form and size of the terminal articulation. Frequently it is obpyri- 
form or rhomboid. Invariably it is of greater breadth than the filament, into which it 
sometimes tapers, e.g. in the young state. But more usually there is a constriction at 
the articulation, and the terminal cell, from its size and shape, appears altogether a body 
of a different kind from the filament. 
The very large sporidia are associated with much oil-globules, as usual of varying size. 
The sporidia themselves are generally oblong, with rounded ends—about 8-locular at 
first—the loeuli transverse, but breaking up gradually in a longitudinal direction into 
smaller loculi and assuming a muriform character. Their size varies considerably with 
 age—from :0009" to :0030" long and :0004” to *0015" broad. In all cases and in all 
stages of growth they are colourless—a circumstance that separates them from the 
similarly shaped sporidia of Rhizocarpon, Lopadium, Umbilicaria, and Stenographa. In 
the old state they break up into the subcubical or subspherical cellules of which they are 
composed, which cellules have, when isolated, a nuclear appearance. In the young state 
the sporidia are simply granular like the protoplasm of the asci. No spermogonia nor 
pyenidia were observed. 
2. L. geminata, Flot. I have seen no Greenland specimens. But in specimens col. 
lected by myself in Romsdal, Norway, in August 1857, and determined by Nylander, 
the asci though generally 2-spored, are sometimes l-spored, about :0036" to :0045" 
long and 0006" to -0009" broad. The protoplasm of the asci frequently becomes dege- 
nerate—then assuming the appearance of irregular, linear or ribbon-like masses, brown 
and granular. The hymenium becomes beautifully blue under iodine; and its section 
forms, in this condition, a fine object under the microscope. The large sporidia are 
generally oblong,' with rounded ends, sometimes oval or subspherical, muriform, with 
sometimes a central constriction of the general mass of loculi within the broad hyaline 
sac which envelopes them. Sometimes, in the old state, these loculi occur as an irre- 
gular agglomeration of subspherical corpuscles of nearly equal size. The colour of the 
loculi in question is brown or olive, according to age. The size of the sporidia varies 
from :0015” to :0018" long and -0008" to 0010” broad. They resemble the muriform 
sporidia of some species of Spheromphale (Mudd, Brit. Lich. p. 281). Tips of para- 
physes and hypothecial tissue deep brown. Externally this lichen has frequently the 
characters of L. petrea and L. atro-alba, from which its sporidia, however, distinguish it. 
But even as respects the sporidia there is a gradual transition from atro-alba to geminata ; 
and the group includes several other lichens which have a most doubtful elaim to the 
position of separate species. 
3. L. petrea, Wulf—Jakobshavn, on gneiss and trap; associated frequently with 
Lecanora cinerea. Apparently comparatively common in the area examined by Brown. 
* Described in Paper on * New Lichenicolons Miero-Fungi" formerly quoted, pp. 518 & 534. 
