1904] JOHNSON—MONOCLEA 26% 
Probably the most serious obstacle of all to putting Monoclea in 
the Marchantiaceae has been the sporogonium, which with its long 
seta and its erect cylindrical capsule has quite the aspect of that of 
certain of the frondose Jungermanniaceae. But even here distinctive 
marchantiaceous characters are not entirely wanting. Thus, for 
example, the wall of the capsule of Monoclea is a single layer of cells 
(jigs. 31, 43), except near the base and a small area at the top. In this 
respect it agrees with all known Marchantiaceae (SCHIFFNER ’93), 
and differs from all the Jungermanniaceae with which it has been 
supposed to be related. For the wall of the capsule of Pellia is well 
known to be three or four-layered, and I have found that of Sym- 
phyogyna to have a similar structure, instead of a one-layered wall 
as is stated by Scutrrner. The slightly developed foot of Monoclea 
has many counterparts among both Marchantiaceae and Junger- 
manniaceae. The seta is probably longer than is found in any other 
marchantiaceous form, but this and the simple type of rupture of the 
capsule, which occurs in isolated cases in both the Jungermanniaceae 
and Anthocerotaceae, are perhaps related in some way to the peculiar 
habitat of the plant. The spores and elaters show, so far as I have 
discovered, no characteristic peculiarities. 
The particular genus of the Marchantiaceae to which Monoclea 
'§ most closely related I am at present unable to suggest. We have 
ern that it resembles certain of the simpler genera in the place of 
ongin of its antheridia and archegonia. These facts seem to me to 
favor CaMPBELL’s view (’98) that the relationship of Monoclea is with 
the lower Marchantiaceae. The occurrence of similar male recep- 
tacles m some of the higher forms, e. g., Fimbriaria and Grimaldia, 
'S probably an instance of the persistence of the primitive type of male 
receptacle side by side with a more highly specialized female one. 
SUMMARY. 
Mo . ets 
“onoclea occurs in Jamaica in very damp places, being usually 
pping water. 
€ male receptacle of Monoclea is only superfically like that of 
F é 
ii since all the antheridia of a receptacle are formed in acro- 
of mete from one growing point. It resembles rather that 
Tsinia and Fimbriaria, 
