OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 111 
As a sort of key to the following memoir, I beg to subjoin a 
Summary of the general characters of Spermogones* and Pycnides,t and their respective 
contained corpuscles, Spermatiat and Stylospores.§ 
I. SPERMOGONES. 
I. External Form.—tThey are generally more or less oval or spherical bodies ; 
sometimes wholly immersed in the substance of the thallus; more frequently 
partly immersed and partly projecting on the surface of the cortical layer: in 
some cases, naked and sessile, seated on the surface of the horizontal thallus, or 
forming the terminations of the ramuscles in the erect fruticulose one. The 
immersed and semi-immersed spermogones are plunged in the substance of the 
medullary tissue of the thallus, and they are usually partly covered by the cortical 
layer, and partly encircled by the gonidic layer. 
Spermogones appear on the surface of the thallus, as :— 
1. Punctiform bodies—In which case they are wholly immersed, the apex 
alone being visible on the thalline surface ; in many Parmelias, in Evernia, Roc- 
cella, Dufourea, and Chiorea. 
2. Conoid or Papilleform bodies—In which case they are semi-immersed ; in 
many Physcias, Umbilicarias, Parmelias, Placodiums, Squamarias, and Pannarias. 
3. Mammilleform bodies—In which case they are sometimes seated on, or in, 
special thalline tubercles ; in many Séictas, Ricasolias, and some Physcias, Par- 
melias, Pannarias, and Coccocarpias. 
4. Discoid bodies—In Collema and Leptogium. 
5. Wart-lke bodies—In Ramalina, Usnea, Thamnolia, Ephebe, and Stereo- 
caulon. The papilleform and mammilleform spermogones also frequently become 
wart-like and very irregular when confluent. 
6. Barrel-shaped or tub-shaped bodies—In Cladonia, some Nephromiums, 
Lichinas, and Parmelias. 
7. Large lecidine bodies—Whitish in Placodium circinatum, var. ecrustaceum ; 
brown in a form of Cladonia papillaria. . 
Externally, the spermogones frequently resemble, and are apt to be confounded 
with,— 
a. Nascent apothecia; as in Ricasolia herbacea. 
b. Pycnides. 
* From omigua, a seed, and yovj, generation, 
 ¢ svmds, compact, or ruavbrqg, a compact series (Latin, Pycnitis), in allusion to the closely ag- 
gregated sterigmata. The designation, Pycnidis, which was originally given by TuLAsNE, is common 
to similar organs, which occur in various fungi, particularly the Hypozyla. 
t onégua, arog, a seed or germ. 
ordaog, a pillar (Latin, Stylus), and ozoge, a seed, from being borne on the end of pedicles or 
stalk-like filaments, called Sterigmata ; crjgrywu, a support. 
