in the neighbourhood of Oswestry and Ludlow. 95 
plant his Gyalecta cupularis, makes the Gyalecta Wahlenbergiana of 
Ach. ‘ Syn.’ his var. 6. of this plant. Now, if what I regard as the 
Gyalecta Wahlenbergiana of Ach. be indeed that plant, I cannot but 
confess my surprise at its being united with marmorea. The two 
plants appear to me ‘“‘toto ccelo distinctz.’” I first discovered the 
Gyalecta Wahlenbergiana about twenty years ago upon the rocks at 
Craig-y-Rhu in this parish, but the habitat there is now lost. I did 
not find it again till the year 1840 upon the Wickliff Rocks at Lud- 
low, where it still grows, investing decayed mosses. This plant 
forms a continuous crust of a pale yellowish colour, and of a sub- 
stance somewhat between leprous and waxy. ‘The apothecia, which 
are numerous, appear to be of exactly the same substance as the 
crust, and are of an urceolate form, having the disc either of a pale 
yellow, or in some instances of a diluted greenish colour. ‘The 
border, which is inflexed, is granulated. The apothecia are far more 
fragile and tender than in marmorea. The plant resembles much, 
upon a very minute scale, the beginning of a honeycomb. Wahlen- 
berg’s description of his plant, ‘‘ substantia mollis et subgelatinosa,”’ 
and its habitat, ‘‘ in locis obscuris supra muscos putridos,”’ agree ac- 
curately with our plant, which indeed I can have no doubt is the 
same as his, and I cannot reconcile myself to its being united with 
marmoreda. 
Lecidea lutea. Upon a single tree at Llanforda, now cut down. 
L. polytropa. Mynydd-y-Myfyr. This is the only English ha- 
bitat I at present know for this plant. 
L. lucida. Upon sandstone walls about Oswestry, in fruit, but 
seldom found in this state. 
L. desertorum. Dr. Taylor, to whom I sent this plant, seems in- 
clined to refer it to ceruleo-nigricans. Mr. Borrer regards it as the 
desertorum of Acharius. I cannot but regard it as distinct both 
from ceruleo-nigricans and from Lecidea coronata, and also from 
guadricolor, with which Ach. unites it. It grows upon the lime- 
stone rocks here with c@ruleo-nigricans, but is much scarcer. It 
differs from this in having the crust more continuous, and in the 
scales of this being far smaller and flatter, and having to the naked 
eye somewhat of a filmy appearance. The shields also have not the 
bluish colour of those of c@ruleo-nigricans, nor are they smooth like 
these, but are of a deep black colour, and appear rough under the 
lens. In qwadricolor again the shields are always some shade either 
of brown, yellow, or red, and the crust not scaly, but granulated. 
The quadricolor too grows upon the earth in heathy situations ; the 
desertorum upon limestone. In coronata again the crust is a conge- 
ries of minute bluish granules which form also the border of the 
apothecia, which are of a reddish brown colour. Fries makes guadri- 
color and desertorum the varieties «. and /3. of his Lecidea decolorans. 
L. canescens. In fruit upon an old oak at Whittington : common 
upon old oaks, but usually barren. 
L. ceruleo-nigricans. Limestone rocks at Pentregaer, Craig-y-Rhu, 
and on the Moelydd. 
L. scalaris. Pales of the Hay Park near Ludlow : scarce. 
