OF FILAMENTOUS, FRUTICULOSE, AND FOLIACEOUS LICHENS. 269 
prominent bodies, seated like horns on the ends of the thalline ramuscles. 
Nyanper likewise describes the spermogones as terminal; but TULASNE describes 
and figures them as seated immediately below the apothecia, and on the same 
ramuscles therewith. The cavity of the spermogone is divided into compart- 
ments, which are very tortuous and narrow. The spermatia are oblong, and im- 
bedded in abundant mucilage. 
Specimen 1.—LEIGHTON exs. 260; Torquay, Devonshire. The plant appears 
to be spermogoniferous only: no apothecia are found; but the very plentiful 
spermogones closely resemble apothecia. ‘They are seated at the angles of the 
fastigiate extremities of the thalline segments as very large and prominent 
spherical bodies of the same colour as the thallus. The ostiole is very minute 
and imperceptible. The spermogonal wall or envelope consists of large, oblong 
cells, of an olive-brown colour, closely aggregated into a compact cellular tissue. 
By placing the ends of any of the thalline segments, bearing spermogones, 
between glass slides in water, and applying pressure, under the microscope, 
the spermatia may be seen issuing from the spermogonal ostioles in myriads. 
They are ellipsoid or oval corpuscles, about izoqth long, and yiath broad, or 
almost atomic as to size, and are given off from the ends of simple, linear 
sterigmata, about jth long, and branching below. 
SPECIES 2. L. conjfinis, Ag. 
According to TuLASNE, the spermogones of this species are either terminal, 
occupying the position I have described those of the preceding species to occupy, 
or they are seated immediately on the apothecia. They are smaller than those 
of ZL. pygmea. The position on the apothecia may be supposed in this and other 
cases to favour the supposition that the contents of the spermogones exercise a 
direct, and probably a fertilizing, influence on the contents of the apothecia. But 
it must be remembered that this site is not a very usual one among the lichens. 
The spermatia are about zath long, and janth broad, on sterigmata which 
measure about ; ath to zath long, and are linear and simple as in LZ. pygmea. 
SECTION II. CoLLeMaA Tribe. 
GENUS I. Sywatissa, DE&, 
This genus has the external aspect of Collema, both in regard to its thallus 
and spermogones. But the spermatia are developed from the apices only of very 
delicate, linear, simple sterigmata, which resemble those of Ramalina. The Sper- 
matia are among the smallest known, being about sth long in §. micrococca : 
they are usually rod-shaped or ellipsoid. 
Sprcigs 1. §. symphorea, DC., 
(Syn. iS. lichenophila, DR.,) which occurs equally,in Africa and Europe. This 
| YOL..XXIl. PART I. Ws 
