278 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
Species 1. JL. fragile, Tayl. 
Specimen 1.—On limestone, probably from Dunkerron, Ireland; coll. TayLor 
himself; in Herb. Carroll (Syn. Collema fragile, Tayl., “Fl. Hib.” 109; Scheer. 
Enum. 259). The plant is allied to ZL. cretaceum, but its thallus is much larger. 
TayuLor remarks, “ Marginal lobes rough with wrinkles and granules ;” and again 
to) gr. ? 5) 
*“ their upper surface rough with granules, concolorous with the thallus, clustered, 
of different sizes, globular, yet flattened at the top.’ The granules described so 
minutely by TayLor are the spermogones of the plant. These organs are scattered 
abundantly over the flat surface of the lobes of the thallus, towards its periphery, 
sometimes extending nearly to the centre of the thallus. They never fringe the 
margins of the lobes. They are pale, brownish-yellow, discoid, immersed bodies, 
precisely resembling those of the majority of the Collemas. They are very con- 
spicuous when moistened, under the lens. The spermatia are rod-shaped, about 
mth long, and yaoth broad, on arthrosterigmata having the characters of those 
of Collema. 
Species 2. L. subtile, Nyl., 
Which includes, as a variety, L. diaphanum, Ach. 
Specimen 1.—Var. diaphanum, Philippine Islands, Cumine; in Herb. Hooker, 
Kew (sub. nom. Collema erythrophthalma, Tayl.) The margins of the extremely 
delicate thalline lobes are fringed with very minute, pale, brownish-yellow sper- 
mogonal warts, which constitute a series of teeth or denticulations, resembling 
those met with in South American forms of L. tremelloides. 
SPECIES 3. JL. tremelloides, Fr., 
A cosmopolite and very beautiful species, which includes, as varieties, the Z. 
azureum, L. marianum, and L. marginellum of authors. 
Specimen 1.—On trees, Muckross Woods, Killarney, Ireland; coll. Carrot; 
with apothecia. This is one of the best species of Leptogiwm in which to study its 
spermogones. In this specimen, however, they are well seen only when moistened. 
They are abundant, resembling grains of mustard-seed, studded along the edges 
of the lobes; their colour is of a pale brownish-yellow, which contrasts strongly 
with the dark leaden-gray of the thallus. Each spermogone is pierced centrally 
by a very minute pore or ostiole. The spermatia are rod-shaped, about yath 
long, and 35;nth broad. 
Specimen 2.—Graham’s Town, Cape of Good Hope; in Herb. Hooker, Kew. 
The spermogones are scattered outside the region of the apothecia, on the flat 
surface of the thallus, not on its margins. They are aggregated or grouped in 
considerable numbers as small, regular, roundish or flattened warts or papille, 
concolorous with the thallus. The body of the organ is semi-immersed only, — 
and consists of a hard, whitish kernel; the ostiole is minute, punctiform, and — 

