182 DR LAUDER LINDSAY ON THE SPERMOGONES AND PYCNIDES 
papillar elevations of the thallus, scattered on the flat surface of the lobes near 
their margin. Occasionally, but rarely, they would appear to occur on the crisped 
and curled margins themselves; in which case, it is impossible to distinguish 
them from those of the preceding species. The cavity of the spermogones is simple, 
reeular, round; the envelope consists of a brownish or olive-coloured cellular 
tissue. ‘The spermatia are rod-shaped or acicular, and about sath long, on the 
apices chiefly of short, simple, inconspicuous sterigmata. 
| Specimen 2.—Owhyhee, Sandwich Islands, 1794; collected by ALEX. MENZIEs ; 
in Herb. Menzies; and also California, 1793; both in Herh. Royal Botanic Garden, 
Edinburgh. The margins of the lobes are fringed with small brown or black 
tooth-like spermogones, as in P. ciliare, to which MENziEs’s plant may perhaps 
really belong. | 
FAMILY XI. Umpinicariz. 
GENUS I. Umpiuicaria, Hofm. 
There is great uniformity in this genus in regard to the internal structure, or 
the contents, of the spermogones. In all the species the sterigmata are articu- 
lated, and the spermatia very numerous, short, and rod-shaped. Externally the 
spermogones vary somewhat. They are always more or less immersed in the 
substance of the thallus; but their ostioles exhibit every gradation of form be- 
tween the papilla and the mere point. Their colour externally is usually black, 
and, as a general rule, ‘they are easily seen in proportion as the thallus is light- 
gray or copper-coloured. Sometimes the spermogones are largish flattened cones, 
or even tubercles, with a depressed apex. These cones may be perched on papillar 
elevations of the thallus, which render them still more prominent. Sometimes 
they are apparent on the surface of the thallus as mere immersed black points, 
flat or depressed. Round these points, which are the ostioles, the cortical layer 
' of the thallus may be ruptured or fissured in a radiating manner, or the thallus 
may form a sort of ring round the black punctiform ostiole. This ostiole is 
usually simple, round, very minute, and inconspicuous. But in old spermogones 
it frequently becomes gaping and very prominent, irregular in form, triangular 
or stellate-fissured. The thallus sometimes appears dotted over with largish 
irregular black perforations, which are the ostioles of old spermogones. More- 
over, the nucleus or body of old spermogones frequently falls out, and irregular 
saucer-like cavities are left. The size of the spermogones varies greatly. They 
may be so minute that they are scarcely visible even under the lens, as in U. 
polyphylla ; or they may be very large and distinct, as in some forms of U. vellea, 
U. hirsuta, and U. cylindrica. In U. proboscidea their diameter is 5th to jth; 
in U. erosa yth to seth; and in U. hirsuta their depth is jth to sth. They are 
generally scattered in large numbers about the margins of the lobes on their flat 

