356 DR. LINDSAY ON WEST-GREENLAND LICHENS. 
into two, giving exit to the contained granules or nuclei. The sporidia, in all their stages 
of growth, bear a general resemblance to those of Physcia stellaris. | Insignis appears to me 
to pass into disciformis, just as the latter graduates into myriocarpa. All three may very 
properly be referred to a single aggregate species or type, the varying size of the apothecia 
and sporidia being altogether a subordinate ** character,” just as it is in the petrea group. 
7. L. myriocarpa, DC.—Egedesminde; Illartlek glacier; Jakobshavn, on birch-bark, 
associated with minor forms of Lecanora subfusca. Several states occur, athalline as 
well as thalline, including forms having the characters of L. punctata and L. pinicola of 
authors. The following were the chief forms met with :— 
(1.) Saxicolous, Egedesminde. On a very irregular, whitish, verrucose (tartareous) 
thallus, associated with a state of Lecanora polytropa. Apothecia subspherical, black, 
small, erowded. Hymenial gelatine beautifully blue with iodine. Hypothecial tissue 
and tips of paraphyses deepish brown.  Sporidia 2-locular, oval or ellipsoid, brown, 
00080" to “00045” long and :00015" to ‘00022 broad. 
(2.) On dead twigs, Illartlek glacier. Apothecia minute and subspherical, black, main- 
taining their black hue under moisture. Hymenial gelatine blue with iodine. Tips of 
paraphyses very deep brown; filaments very deep blue with iodine. Asci pale blue with 
iodine, :0015” long and :0006" broad; 8-spored. Sporidia 2-locular, brown or olive, 
ellipsoid, straight or slightly curved, sometimes figure-8-shaped. In young state 
frequently simple, sometimes containing nuclei instead of loculi. Size about -0005” to 
"0006" long and :0002” to :0003” broad. 
(3.) Athalline; parasitic on the white (bleached) decayed thallus of various Umbilicarie. 
Apothecia small, black, crowded, subspherical, nearly superficial, the base only being 
slightly sunk in the alien thallus. Hymenial gelatine blue with iodine. Asci 8-spored, 
00150” long and :00045” broad. Sporidia variable in size and shape, 2-locular, ellipsoid 
or oval, sometimes figure-8-shaped*, olive, :00045” long and *00015" broad. 
I believe, on the one hand, that systematists of the modern Continental school of 
lichenology would make a separate species of the last-named “ form ” or condition of myrio- 
carpa, simply because it is athalline, and occurs in an unusual habitat in a foreign 
country; and, on the other, that many so-called athalline parasitic * species” of Lecidea 
are mere conditions of commonly spread types (e. g. parasema and disciformis). 
8. L. discoénsis, n. sp.t Thallus subfoliaceous or parmelioid, microphylline, whitish 
or grey, resembling that of some forms of Physcia stellaris. Apothecia (only one mature) 
those of a Lecidea, both the flat disk and inconspieuous exciple being black. Sporidia 
resembling those of the stellaris group of Physciæ in size, colour, and form, being 2-locular, - 
oval or ellipsoid, straight or somewhat curved, deep olive, 0006” to "0009" long, 00030" 
to 00045" broad. Asci 8-spored, :0030" long, 0009" broad. The plant bears certain 
resemblances to ZL. grenlandica, which differs in the colour of its thallus and the 
structure of its sporidia. It has also certain points of resemblance to Physcia obscura, 
* Figure-S-shaped sporidia differ from those that are soleæform by the equality of the halves of which they consist. 
The upper half of the soleæform sporidium is broader, longer, or otherwise larger than the lower. 
t The specific name discoénsis is borrowed from the island of Disco. 
