STEMONITIS.] STEMONITACE^. HI 
minute spines are arranged in the same manner as in a., either gmng 
a close or open reticulation on the surface of the spore or grouped 
more or less in clusters (not evenly distributed as in the faintly warted 
spores of S. splendens). These two varieties represent well-marked 
centres, but there is no definite boundary between them denotmg a 
true specific difference ; sporangia widely differing m length and with 
long or short stalks may have spores of either form ; y. occurs with 
both large and small spores. Rostafinski's types of S. fusca from Vera 
Cruz (B. M. 631) and from Ruda Guzowska (Strassb. Herb.) have the 
spores not smooth, as he describes, but of a form intermediate between 
a. and /3., 7 to 8 /x diam., with about 28 meshes of reticulation on the 
hemisphere. S. clictyospora Rost. appears to be an unnecessary name ; 
it is represented in Kew Herb, by the two types referred to in Rost., 
Mon., App., p. 27 ; one from Ceylon (K. 1622) bearing the signature 
of Rostafinski is S. fusca Q. and has small spores 5 to 6-5 /x diam., 
reticulated in the same manner as in the Strassburg type of S. fusca, 
but more faintly ; the other type is from Venezuela (K. 1620, B. M. 
648) on a palm leaf, and in poor condition ; it was marked by Berkeley 
S. trechispora; the spores are 10 to 12 /x diam., with a strong complete 
reticulation in the form of raised bands giving an even border to the 
spore 1 jj. broad. These examples might be taken as representing the 
extreme limits in size and reticulation of the spores of S. fusca. The 
specimen from Yenezuela, however, differs so considerably from its 
nearest allies in the strong and banded reticulation of the spores, that 
it is a question whether it might not be retained for the present as a 
distinct species under Berkeley's name of S. trechispora. A type speci- 
men of S. maxima Schwein. received from Dr. Rex of Philadelphia (2697, 
N. American Fungi, Ellis and Everhart, L:B.M.82), has the spores 7_/x 
diam., with reticulation precisely of the form ai)ove described in 
Rostafinski's type of S. fusca in Strassb. Herb. The -type of S. 
nigrescens Rex, kindly furnished by Dr. Rex, has dark spores as in a., 
but only 7 /x diam. S. Castillensis Macbride, from Nicaragua (B. M. 
1002) presents no characters by which it can be separated from S. 
fusca /3. ; the spores are distinctly reticulated, and measure 6 to 7 ju. 
The confluent form of the sporangia is in some cases seen throughout 
the whole development from one plasmodium, the capillitium con- 
sisting of a profuse network of arching threads, with broad expansions 
at the nodes, but sometimes only a part presents the confluent form, 
and is associated with more or less perfect sporangia with the normal 
superficial net. An exceptional form of y. confluens is figured in Plate 
LXXVII. (L:B.M.82) ; it was found in Epping Forest developing 
from white plasmodium on dead leaves near rotten wood. The 
sporangia are combined into a convolute Eethalioid mass, the mem- 
branous sporangium-walls are to a great extent persistent ; no stalks 
are developed, but in one case the whole eethalium is suspended by a 
long slender thread of hypothallus ; the columellce are wanting, and 
the capillitium is represented by a scanty network of irregular threads 
with many wide expansions, attached at the extremities to the 
sporangium - walls. The spores are perfectly formed, 6 /u, diam., 
minutely warted, with the warts here and there connected by faint 
lines suggesting the appearance of a reticulation. This development 
is interesting as showing to what extent variation may occur ; if it 
were not connected with the type with intermediate forms, the position 
of the specimen might be diflicult to determine. The description and 
figure of Amaurochit'.te speciosa Zukal (Lc.) leave little doubt that his 
species is the form y of S. fusca. 
