236 DR. LINDSAY ON THE SPERMOGONES AND 
and most beautiful, as well as most puzzling, spermogones that occur among lichens. 
Thus the largest that occur in Lecidea are (in L. Ehrhartiana) irregular flattish warts, 
which resemble Lecideine apothecia. Next in size are the tubercles or cones of L. abietina. 
These larger forms are frequently wholly, or nearly altogether, superficial, seated on, and 
scarcely in, the thallus; they are sometimes confluent, becoming very irregular warts (as 
in fusco-atra). Occasionally they closely resemble nascent apothecia, as in cupularis. 
(c) Colour is most frequently black, whatever be the form. Sometimes this blackness 
is covered with a white pruina, as in L. abietina. Brown is, perhaps, the next com- 
monest. Not unfrequently they have the same colour as the thallus or apothecia. In 
the former case they are sometimes very inconspicuous and difficult of detection, as in 
Jusco-atra and its allies. They are here immersed, as they are also in contigua, parasema, 
and rivulosa. In L. pineti, L. cupularis, and the whole of the Gyalecta group, they are 
concolorous with the apothecia. In decipiens they are orange-red, resembling those that 
are typical in that section of the Lecanore which includes aurantiaca, ferruginea, and 
Lallavei. | 
(d) Ostiole. 'The aperture by which the spermatia are discharged (where it exists or is 
at all conspicuous) is most frequently punctiform, forming, or seated on, the apex of the 
oval or subspherieal spermogone. Sometimes it is stellate-fissured ; and if in this case it 
is also largish and black, it may assume an Arthonioid character, as in some forms of 
fusco-atra. It is often subpellucid, especially under moisture, as in some forms of para- 
sema. Frequently it is whitish or grey, concolorous with, or very slightly darker than, 
the thallus, in which case it is usually difficult of detection, even under moisture. Some- 
times, however, it is girt with a pale sorediiferous thalline border, as in some forms of 
fusco-atra, which renders it more readily distinguishable. Frequently, from its great 
minuteness, it is inconspicuous ; in other cases, such as the Lecideine forms of spermogone, 
an ostiole does not exist at all. 
(e) Size of €— Its vertical diameter in cdit is 159, in canescens 113; 
the transverse 3); to ṣọ in cupularis, à in decipiens, 25 to 433 in conglomerata. When 
the body of dis so dll is immersed, only the punctiform ostiole is visible on the sur- 
face ; and this, as already stated, is frequently so minute as to be invisible in the dry state 
to the unaided eye; on the other hand, the spermogones attain the size of sago-grains, 
which they somewhat resemble, in some forms of abietina and luteola, where they are 
comparatively superficial 'and tuberculate or conoid. In these cases they are conspicuous 
in the dry state to the naked eye. 
(f) Cavity is generally simple, but sometimes it is compound, consisting of several 
narrow anfractuosities, as in decipiens and cupularis. Its envelope or walls consist of 
cellular tissue, which is generally some shade of brown, though sometimes it is bluish, as 
in evilis. 
(g) Spermatia are most generally straight and delicate, acicular or linear. In some 
forms of vernalis they are ellipsoid. In a few species (parasema, conglomerata, pulvinata) 
they are curved or twisted, as in Lecanore of the groups subfusca and varia, and their 
allies. Their size is very variable. The longest are those which are subvermiform, as in 
parasema and conglomerata, where they are 4455 to 5255. Next in size are the peculiar 
