PYCNIDES OF CRUSTACEOUS LICHENS. 283 
mogones in question as belonging to the lichen in intimate connexion with which they 
occur. 
Species 8. A. GREGARIA, Weig. (Mudd, Br. Lich. p. 249— 4. cinnabarina, Fr.). 
Specimen 1. Var. astroidea, Leight. On holly, Killarney: Carroll, March 1858; as- 
sociated with Thelotrema lepadinum, Ach., and Verrucaria epidermidis, Ach. Lirellæ 
very delicate, small, narrow, substellate. Spermogones scattered among the lirellæ as 
very minute, black, punctiform bodies, with simple cavity and deep-brown cellular enve- 
lope. Spermatia rod-shaped, 5555 X 30000 on short, simple, linear sterigmata. 
Specimen 2. Var. marginata, Leight. Ingleby Park, Cleveland: Leight. Exs. No. 250. 
Spermogones scattered among the lirelle as very minute Verrucarioid conceptacles, 
scarcely distinguishable unless under moisture. Spermatia in myriads, very minute, 
oval, ellipsoid, or pyriform, on very short, simple, linear sterigmata. From among and 
beyond the latter project delicate, ramose, sterile filaments, as in Ramalina and other 
genera. Cellular matrix of the sterigmata brown. The irregularity of form in the simple, 
eolourless spermatia, is quite as great as in many stylospores. 
Genus IV. STIGMATIDIUM. 
The spermogones are minute, black or brown, punctiform, immersed, generally on 
separate thalline areole from those occupied by the apothecia, and outside the central 
parts of the thallus, on which the apothecia are grouped. "They have a close external 
resemblance to the apothecia when the latter are isolated and punctiform; but the 
apothecia frequently become lirellæform from aggregation and confluence, which the 
spermogones never do. The spermogonal cavity is simple; the envelope brown. The 
spermatia are linear and straight, contrasting in this character with a genus which 
somewhat resembles Stigmatidium, viz. Chiodecton, in which the spermatia are curved. 
Their usual breadth in Stigmatidium is 33455; their length varies from 5755 to 5506 in 
crassum ; in venosum itis 5555. The sterigmata are simple, short, linear, of equal width 
to the spermatia; in venosum their length is 53555 — sopọ. Occasionally, as in crassum, 
elongated, delicate, sterile filaments project into the spermogonal cavity, from among 
and beyond the fertile sterigmata. 
Species 1. S. CRASSUM, Dub. 
Specimen 1. On old bark, Rostellan, Cork Harbour: Carroll  Spermogones are 
abundant outside the region of the apothecia as never confluent, but thickly scattered, 
brown, npe bodies, becoming pale and pellucid on moisture, containing rod-shaped 
spermatia sovo X 30500; On linear sterigmata, 7055-3000 long, bifurcating from the 
base, like those of Ephebe pubescens or various Cladonie *. 
About the black hypothalline boundary-line, in one specimen, are scattered, in a 
series, numerous very minute, black, punctiform spermogones, with ellipsoid or spherical 
spermatia in myriads, about 30-000 — 15.500 in diameter; on very short, simple, linear 
sterigmata. Cavity simple; envelope of deep-brown cellular tissue. 
* As figured in my first Mem. Spermog., plate xv. fig. 30, and plates vii. and viii. 
