18 EPHEBACEI. [GoNIONEMA. 
satisfactory diagnosis, and are consequently omitted. Among these are 
several species of Sirosiphon, e.g. S. saxicola Naeg., S. alpinum Kiitz., 
8. pulvinatus Bréb., S. ocellatus Kiitz., which occur in Great Britain and 
Ireland. According to Nylander, in Lamy Mt. Dor. p. 1 (note), Raco- 
dium ebeneum (Dillw.), which from general appearance might be sup- 
posed to belong to this tribe, has no analogy with Strosiphon, but is 
quite different in struc- 
ture, containing gonidia, 
and is probably some 
peculiar sterile Lepraria. 
1. GONIONEMA Nyl. 
Mém. Soc. Cherb. iii. 
(1855) p. 163; Syn. i. 
p. 88.—-Thallus byssaceo- 
fibrillose, tubuliform, in- 
tricate; gonimia . sub- 
moniliformly connate in 
one continuous series. 
Apothecia biatorine or 
gyalectoid; spores 8ne, 
simple, paraphyses slen- 
der; hymenial gelatine 
(especially the theca) 
bluish, becoming wine- 
red or tawny wine- 
coloured with iodine. 
Spermogones lateral, or 
terminal, globose; ste- 
rigmata simple, slender ; 
spermatia oblong, very 
minute. 
Various Scytonemas 
probably belong to this 
genus. If this be so, the 
more recent name must 
give place to that of 
Scytonema Ag., in its 
stricter sense. 
1. G@. velutinum Nyl. 
Mém. Soc. Cherb. iii. 
(1855) p. 163.—Thallus 
very thin, densely pan- 
nose, intricate, brownish 
when moist, dark-brown 
when dry. Apothecia 
minute, terminal, ap- 
wins S&S 
Fig. 1. 
Gonionema velutinum Nyl.—a. Filaments with 
two apothecia, x 30. 0. Vertical sections of 
two apothecia, x 30. +. Filaments with 
three spermogones, x 30. d. Short frustule of 
thallus, and d' transverse section of the same, 
x 350. ¢. Apex of a filament containing a 
meiogonimium, x 200, and e' fragment of a 
syngonimium composed of four gonimia, 
x 350. f. Sterigmata and spermatia, x 500. 
g- Theca and paraphyses, x 350. 4. Three 
spores, X 500. 
pressed, somewhat concave, dark-brown, pale within, the margin 
tumid; spores ellipsoid or oblongo-ellipsoid, 0,010-0,015 mm. long, 
0,006-0,007 mm. thick.—Nyl. Syn. i. p. 88, t. 1. £ 11; Leight. . 
