PYCNIDES OF CRUSTACEOUS LICHENS. 211 
spermogone is about 357 inch deep in L. subfusca, the transverse dimension being about 
¿ of the depth. In L. cervina the depth is 545 to 545 inch, the transverse diameter about 
the base being nearly as great. In Z. ferruginea the depth is about ṣẹ inch. The sterig- 
mata are generally short and simple; sometimes ramose or Rubens of a few articu- 
lations. Short, simple sterigmata are frequently vesicular or subspherical, as in L. 
glaucoma, sulphurea, parella, varia, milvina, torquata. The simple forms may also be 
variously elongated, and either regularly linear or variously bulging, with wavy outline. 
Arthrosterigmata also occur—of a few articulations—sometimes elongated, linear, simple 
cells, as in L. tartarea, atra, and sophodes; or composed of numerous short and sub- 
spherical, or subcubical ones, as in L. aurantiaca, ferruginea, and cervina. The length 
of the sterigmata or arthrosterigmata varies from 345 to 3057 inch: being from 535 to 
sty in L. atra and aurantiaca; 755 to 1005 in L. subfusca and erysibe; 5555 to 1559 in 
L. tartarea, ventosa, and sulphurea; +555 to 395g in L. parella; and soso to 3055 in L. 
milvina, olivacea, and leucolepis. Hypertrophied, sterile, elongated filaments accompany- 
ing the fertile sterigmata seldom occur in this genus; but they are met with in Z. cinerea 
and some forms of L. subfusca (e.g. epibrya). The spermatia eid in length from 41355 
to 45.559, being 105 to 1959 in L. subfusca and frustulosa ; 13,5 to 5555 in L. atra, 
varia, sulphurea, and ei 5060 tO sooo in L. tartarea, parella, ventosa, milvina, 
and leucolepis; 5555 to sooo in L. sophodes and torquata; and 3055 to 1505 in L. au- 
rantiaca, ferruginea, cerina, and cervina. Their breadth is generally between 355055 and 
30500 being 153555 to 13505 in L. cerina and olivacea, and 35555 to 35400 in L. Lal- 
lavei. They are straight and linear, needle-like or rod-shaped in L. atra, cinerea, milvina, 
sophodes, turfacea, and olivacea: curved or twisted in L. subfusca, varia, frustulosa, sul- 
phurea, glaucoma. 
Species 1. L. PARELLA, Ach. 
Specimen 1. Yeadon, Yorkshire: Dr. Carrington. Apparently saxicolous; subisidioid 
and sterile. Sent me sub nom. Zsidium coralloides*. Thallus consists of a series of very 
irregular pale warts, which in the dry state appear all to possess the same sterile cha- 
racter. But under moisture some of them are seen to be marked with a very pale brown, 
indistinct, apical ostiole, which indicates those that contain spermogones. lt may 
further, then, be observed, that the spermogonal warts are generally the largest and 
most irregular, sometimes resembling nascent apothecia. But many, if not most, of the 
spermogonal warts are destitute of an ostiole; and they are distinguishable from the 
ordinary thalline ones only on section and microscopical examination. It is then seen 
that the sterile thalline warts exhibit nothing but white medullary tissue, whereas the 
spermogonal ones exhibit a nucleus of a pale flesh-coloured, or pale brownish-yellow, 
tissue, greedily absorbent of water, becoming subgelatinous under its influence, re- 
sembling in colour and consistence the tissue of the young hymenium. The cavity of 
the spermogone is made up generally of two or more convergent, narrow, and most irre- 
gular sinuses or canals. The sterigmata are subsimple, branching digitately from their 
* Doubtless an error, 7. corallinum being intended. 
