Pur 
268 DR. LINDSAY ON THE SPERMOGONES AND 
gones occur. What appear to be degenerate apothecia are really irregular, roundish, 
confluent groups of spermogones. When isolated, these spermogones are largish, black, 
- irregular, prominent tubercles, frequently more or less covered with the same white 
pruina that covers the thallus. The spermatia are linear, straight, frequently slightly 
curved, «oss X 20500. on sterigmata about 1365 — 3955 long, ramose as in Ramalina, the 
segments linear. Nylander (Prod. p. 121) places candida in that section of the Lecidee 
which possesses arcuate spermatia, a section that includes parasema, conglomerata, and 
aromatica. 
Species 42. L. suBLURIDA, Nyl. (= Thalloidima, Mudd, Brit. Lich, p. 172). 
Specimen 1. In crevices of Old Red Sandstone rocks, by the shore, Ballycotton, co. Cork: 
Carroll, Mar. 1858. "Thallus olive-green, this colour being probably due to the shaded 
character of its habitat. The plant has much the aspect of a form of Squamaria crassa, 
Ach.; but its spermogones and spermatia at once distinguish it, as do also the sporidia. 
The spermogones are abundant, and are quite those of L. lurida. They are scattered 
over the thalline squamules as small brown tubercles, pierced with a chestnut-coloured 
ostiole, surrounded by a pale thalline halo. Their envelope is of brown cellular tissue. 
Old portions of the thallus are studded over with perforations, which are eroded, obsolete 
spermogones. In this condition the plant resembles similar states of various Umbili- 
cariæ*. The spermatia are rod-shaped, r4455— 15500 X 55000 On arthrosterigmata 
about taso X rasoo: 
Specimen 2. On sea-rocks, near Bangor, July 1802; and on rocks by the sea, Miss 
Hutchins, No. 19, probably Irish; both in the Kew herb., fastened on the same sheet, 
sub Lichen squamatus, Dicks. Both specimens have the characters of No. 1. In Miss 
Hutchins's plant the thallus is much paler than in the other, probably from a difference 
in their respective exposure to light, the paler thallus growing probably in shady crevices. 
A similar phenomenon is common in Physcia aquila. In both plants the apothecia are 
distinetly Lecanorine in the young state, having a thalline margin, and so far differing 
from L. lurida, whose apothecia, however, they resemble in the old state, when the 
margin is obliterated and the disk becomes convex. In the Bangor plant, spermogones 
are scattered about the margins of the thalline lobes as deep-brown, immersed, puncti- 
form bodies. 
Species 43. L. LURIDA, Swartz. (=Psora, Mudd, Brit. Lich. p. 170). 
Specimen 1. Sent by Miss Hutchins to Dr. Hincks: in herb. Carroll; no habitat 
given, but undoubtedly Irish. The specimen is most interesting, as showing all stages of 
development of the apothecia, from the young Lecanorine to the mature Biatorine con- 
dition. Hence this species would appear, like many other lichens, equally referable to 
Lecanora and Lecidea, The spermogones are scattered, immersed, marked on the surface 
of the thallus by a brown ostiole, deeper in colour than the thallus. The spermatia are 
rod-shaped, 555556 X 0.000, Seated on what are apparently arthrosterigmata. 
Specimen 2. Waltham, Yorkshire, Dr. Carrington. The spermogones are largish, 
* Vide first Mem, Spermog. p. 182. 
