COMATRICHA.] 
STBMONITACEiE. 
117 
The genus Comatricha is a somewhat artificial one ; it mcludes 
species which agree with Lamproclerma in all characters but the per- 
sistent sporangium-wall, and with Stemonitis in all but the presence of 
the superficial net of the capillitium ; in C. typhoides the surface net is 
often developed on the lower half of the sporangium ; at the same 
time it is a useful genus, typically marked by the uniform network of 
the capillitium and by the isolated, not fasciculate, growth of the 
sporangia. 
KEY TO THE SPECIES OF COMATRICHA. 
A. Spores dark, brownish-violet, or grey : — 
a. Spores nearly smooth — 
CapilHtium dense, crisped, and flexuose throughout ; on 
-wrood. 1- ohtusata 
Capillitium large, primary branches stout and nearly 
straight ; on wood. 2. C. laxa 
h. Spores spinulose — 
Sporangia globose ; on leaves. ^ 3. C lurida 
Sporangia much elongated, slender and cylindrical ; on 
wood. 4. C. longa 
B. Spores pale, lilac, or reddish-lilac : — 
a. Spores marked with a few widely scattered warts, the 
remaining surface nearly smooth or delicately reti- 
culated, 4 to 6 /A diam. ; on wood. 5. C. typhoides 
h. Spores spinulose, 6 to 10 /a diam. — 
Sporangium-wall completely evanescent ; on leaves. 
6. C. Persoonii 
Sporangium- wall persistent at the base as a membi-anous 
cup ; on leaves. 7. C. ruhens 
1. Comatricha obtusata Preuss, I.e., p. 141 (1851). Plas- 
modium watery-white, in rotten wood, maturing at the place of 
emergence. Total height 1 to 6 mm. Sporangia globose, ellipsoid 
or cylindrical, stipitate, scattered or gregarious, about 0'6 mm. 
diam., purplish-brown ; sporangiuui-wall evanescent. Stalk 
subulate, slender, black, shining; in the globose form usually 
2 to 6 times the length of the sporangium ; equalling the length 
of the sporangium, or shorter in the cylindrical form ; rising 
from a more or less distinct hypothallus. Columella reaching to 
half the height, or nearly to the apex of the sporangium, branch- 
ing above and continued into the capillitium. Capillitium a more 
or less dense tangle of purplish-brown threads, springing from all 
parts of the columella, anastomosing and branching in semi- 
circular curves; of nearly equal thickness throughout, the 
ultimate branches looped, showing few free ends, but connected 
