PYCNIDES OF CRUSTACEOUS LICHENS. 233 
Genus II. URCEOLARIA. 
. The spermogones of this genus resemble those of Pertusaria in being very indistinct, 
and difficult of discovery. They are scattered generally over the warts, which compose 
the thallus, but sometimes are seated on the exciple of the apothecia. The ostiole is 
generally pale, though sometimes blackish, flat, or depressed, seldom if ever papillæform, 
round, or stellate-fissured. ‘The spermogones and their cavity are usually simple; but 
sometimes the former are confluent, and the latter compound, consisting of various sinuous 
chambers. The depth of the spermogone is about ;35; the transverse diameter is a 
little less in scruposa. Spermatia are rod-shaped or ellipsoid, about gogy long, and 55-555 
broad in scruposa. Sterigmata are ramose at the base, with linear, simple segments, 
about 1755 long in scruposa. 
Species 1. U. scruposa, Ach. 
Specimen 1. Var. arenaria. France, Nyl. Exs. No. 46. Spermogones are abundant 
as minute, blackish, depressed ostioles, crowning thalline warts. Spermatia are straight, 
rod-shaped, 5555 long, and sosoo broad, seated on digitate irregular sterigmata, about 
soo long. The sterigmata here are not quite so simple as they are figured by Tulasne 
(Mém. plate iv. fig. 3). 
Specimen 2. Var. cretacea, Sch. On ground in the Lower Vallais, Switzerland, Scheer. 
Exs. No. 201. Spermogones are very difficult of discovery, and very indistinct, crowning 
warts of the thallus, and scattered among the apothecia; frequently resembling very 
young apothecia, the ostiole being stellate-fissured, or obscurely marked. Spermatia 
are sublinear, not quite agreeing with the characters of those figured by Tulasne; 55455 
long and 5455 broad, seated on closely arranged, simple, longish sterigmata. 
Genus III. PERTUSARIA. 
As a general rule, its spermogones are most difficult of detection, on account of the 
extreme pallor and indistinctness of the ostiole, and the circumstance of the body of the 
spermogone being wholly immersed. Occasionally the pale ostioles may be discovered, 
especially under moisture, scattered on the irregularities or warts of the thallus. But 
more generally it is necessary to make repeated vertical sections of the moistened thallus 
in order to their discovery. The envelope is pale and undistinguishable generally from 
the surrounding white medullary tissue. But the internal tissues have the pale rose- 
colour of the hymenium of the apothecia. "Typically the ostiole is round; but more 
generally it is variously elongated, triangular, or stellate-fissured. In exceptional cases 
it is black and papillæform, as in some forms of glomerata. In ceuthocarpa (if what I 
saw were really the spermogones of that species) they are, sometimes at least, largish, 
flat, brown, pellucid spots, occurring in groups on separate sterile portions of the thallus. 
The spermogonal cavity is, as in Urceolaria, simple or compound; in the latter case con- 
sisting of two or more sinuous, convergent divertieula. Spermatia are small and straight, 
linear (rod-shaped) or ellipsoid; their length goog in glomerata, 5555 in communis; their 
