PYCNIDES OF CRUSTACEOUS LICHENS. 273 
young, or are mere segments (halves) of mature or old ones. Sterigmata are short and 
simple. | 
Specimen 14. On fir, Carrigaloe, Cork harbour: Carroll. Thallus is white and sub- 
pulverulent. Lirellæ are disposed in stellate groups, entitling this form to the appel- 
lation, by systematists and nomenclators, of astroidea. Spermogones are very abundant 
outside the region of the apothecia as round, black points, very distinct from their con- 
trast with the colour of the thallus. Spermatia as in Nos. 4, 6, 7, and 13, cylindrical, 
curved, 3555 X 55-000 0n short, simple sterigmata. 
Specimen 15. On trees, Glen Nevis, Aug. 1856: W. L. L. Associated with Verru- 
caria biformis, Borr. Spermatia as in No. 13, on subspherical simple sterigmata. Both 
spermatia and sterigmata resemble those of some forms of Lecidea parasema, though the 
spermatia of the Opegrapha are much shorter, and are curved only in one direction. 
Spermogones accompany O. vulgata in a specimen from Oldenham, near Watford, Hants, 
1819, Menzies, in the Menziesian herbarium of the Royal Botanic Garden, Edinburgh, 
sub O. stenocarpa, var. denigrata—and in another from Suffolk, apparently collected by 
Sir Thos. Gage, in the herbarium of the British Museum. 
Specimen 16. Var. stenocarpa, Ach. Weir coppice, near Shrewsbury: Leight. Exs. 
No. 22. Associated with Graphis scripta, L. Spermogones are large, round, prominent dots. 
Spermatia are crescentic, very numerous and distinct, on simple, vesicular sterigmata. 
Specimen 17. Gloddaeth, near Conway, Caernarvonshire: Leight. Exs. No. 69. Asso- 
ciated with Stigmatidium crassum. A few spermogones occur as large, prominent, black 
papillze on small circumscribed white patches of thallus. Spermatia are of the character 
of Nos. 13, 15, and other specimens, resembling those of Z. parasema in being not only 
cylindrical and curved, but also variously bent or twisted. The spermatia of the Ope- 
grapha here differ from those of L. parasema only in length. The spermogones of the 
Opegrapha cannot be confounded with those of the Stigmatidium, which are very minute, 
punetiform, immersed in an olive-coloured thallus, and contain short, straight spermatia. 
Specimen 18. On bark, Bryn Maelgwyn, near Conway, Caernarvonshire: Leight. Exs. 
No. 194. Spermogones are abundant, large, distinct, round, elevated points, scattered 
among the apothecia on the whitish smooth thallus. The spermatia are here again 
shortish, and cylindrical, curved, of equal width throughout, with rounded ends. Sterig- 
mata are simple, thickish, sometimes irregular in outline; with the spermatia attached 
they have quite, as is common in this species, the appearance of a sickle, of which they 
form the handle, while the spermatia constitute the blade. 
Specimen 19. Scher. Exs. No. 582. Associated with Lecidea quernea. The spermo- 
gones form a mass of small black dots, containing spermatia of the character of those of 
No. 18, 5500 long, on short, simple sterigmata. 
Specimen 20. Var. siderella, Ach. On beech, Switzerland: Scher. Exs. No. 96, sub 
O. rufescens, var. siderella. Three forms of spermogone occur, if we may judge by the 
size of the spermatia. Externally the spermogones are alike, being small, brown, round, 
superficial punctiform conceptacles, scattered aboui or among the lirelle, their enve- 
lope of deep-brown cellular tissue. In all cases the spermatia are cylindrical, and mostly 
curved, with obtuse or rounded ends. But in one set of spermogones they are greatly 
