324 The Botanical Gazette. [June, 
well as the antheridia, resemble those of Rhipidium, being 
spherical, without encrustation, and containing an abundant 
peripheral protoplasm. The antheridia, also, are exactly 
like those of Rhipidium, and apply themselves to the oogo- 
nium in the same position and in the same way; perforating 
the wall without indentation. On the other hand the genus 
differs from either of the other two in possessing two kinds 
of sporangia, one of which is identical with the type found 
in Sapromyces, as has been already mentioned, the other 
quite different in shape and furnished with numerous promi- 
nent spines; while the oospore is unique from the fact that 
it becomes surrounded by a cellular envelop derived from the 
peripheral protoplasm. The antheridial filaments, moreover, 
arise from special segments which are always derived from 
the same segment that produces the oogonia which they fer- 
tilize, and grow downward to the base of the latter, often pro- 
ducing one or more branches, each terminated by an anthe- 
ridium. 
In view of the presence of spinose sporangia borne more 
or less umbellately, it seems not improbable that the fungus 
just described may be very properly considered, at least pro- 
visionally, as generically identical with Rhipidium spinosum, 
since all we know of this species from the figures given by 
Cornu is that the sporangia may be oval to oblong an 
spinose,* or piriform and unarmed, 18 and that they may be 
sub-umbellately borne. 14 
In view of the various distinctions above enumerat wear 
provisional summary of the members of the Leptomitace® 
may be indicated as follows; the group being separated 35 @ 
distinct family in accord with the classification adopted by 
Schroeter in his revision of the Phycomycetes. ** It may be 
said, however, that should the family be united with any 
other, it must evidently be with the Pythiacee, if we Borger 
nize them as distinct from the Peronosporacee, OF W 
latter if we do not; since their reproductive processes © 
with those of the two last mentioned families rather than 
those of the Saprolegniacee. It will be observed that 0 ‘ 
following synopsis, Gonapodya has been retained in the re 2 
where, in the writer’s opinion, it may be provisionally place 
per th caiman cerrado ri ee 
WT Fe eas 
a4) 6. fe 6. 
*SEngler und Prantl, Naturl. Pflanzenfam. 93: 101. [Th. I. Abth. #] 
n with 
