234 DR. LINDSAY ON THE SPERMOGONES AND 
breadth 44-155 in ceuthocarpa, +5 455 to 35505 in other species. Sterigmata are simple or 
slightly ramose, sometimes wavy or irregular in outline, or very delicate and filamentous 
(in communis); occasionally of equal breadth with the spermatia. Their length varies 
from 155g to 1255 in communis and ceuthocarpa, to 56655-50605: With a breadth of -0400 
in glomerata. 
Species 1. P. GLOMERATA, Sch. 
Specimen 1. Ben Lawers, in the Kew herbarium. Apothecia are separate and urceo- 
late, the hymenium being, at least partly, open or exposed. Spermogones sometimes 
closely resemble the young apothecia, when the ostiole is largish and distinct. The said 
ostiole is generally not quite round, but approaches stellate fissuring. More generally it 
is minute, black, and punctiform, crowning the smaller thalline pulvinuli. The body of 
the spermogone is immersed, and its cavity apparently simple. Spermatia are rod-shaped, 
5000 long and 35555 broad, seated on simple sterigmata, about zooo to 3955 long, and 
10500 broad. Basal cellular tissue deep brown. The plant closely resembles Lecanora 
verrucosa, Ach., which grows with it in the same alpine habitats. 
Species 2. P. CEUTHOCARPA, Sm. & Borr. (not Fries, =PORINA, Tayl. Fl. Hibern. p. 102). 
Specimen 1. On red sandstone rocks, co. Kerry. Associated with the ordinary thallus 
of the Pertusaria are two circular, rosette-like patches of different character, resembling 
some forms of the thallus of Squamaria saxicola. Their colour is pale green, but they 
are as rugulose as the thallus of the Pertusaria. On or between the areolæ of these 
separate patches of thallus are seated spermogones externally resembling apothecia; they 
are pale reddish-brown, pellucid or semipellucid under moisture. The cavity is irregular, 
the basal cellular tissue of the sterigmata very pale brown. Spermatia have all the cha- 
racters of those of P. communis, being straight, short, linear or subellipsoid, about 45-5355 
long and 35005 broad, seated on delicate linear sterigmata, branching slightly below, 
about toso to 5560 long, and scarcely exceeding in breadth the spermatia, becoming 
elongated and hypertrophied in age. The spermatia are certainly not those typical of 
S. saxicola, which are long, filiform, and curved. The thallus, on the other hand, is 
very different from that of the Pertusaria: and, nevertheless, the spermogones and their 
contents have the characters of those of Pertusaria, and are probably to be referred to 
the present species. 
Species 3. P. FALLAX, Pers. 
Specimen 1. On basalt, Blackcairn Hill, Newburgh, Fifeshire, W. L. L. "Thallus very 
dark grey. Spermogones wholly immersed, marked by a pale ostiole. No spermatia 
seen. 
Species 4. P. PUSTULATA, Ach. 
Specimen 1. Leighton's Exs. No. 230. Two forms of spermogone occur, according to 
the character of the spermatia; externally alike, forming a patch or group by themselves 
of small, brown, subtranslucent spots, at the left-hand corner in my copy. In one form 
