42 A. J. W. Hornby. 
and E. polymorpha, described by Professor West 1 as epiphytic on a 
species of Pithophora , and the one described above. All three have 
much larger dimensions than the other species of this section, and 
it should be noted that E. polymorpha and E. Cladophorce some¬ 
times contain more than one pyrenoid. 
Moreover, though the branches of E. Polymoryha do anasto¬ 
mose, it is only in E. Cladophorce that there is the extraordinary 
development of thallus, leading to the formation of compact 
masses. This is characteristic of the “ Ectochcete ” group, Huber’s 
three species E. leptochcete, E. endophytum and E. yadinianum, 
and in the latter species, this tendency is brought to the highest 
point; there is often formed by the anastomosing of filaments 
growing away from the host-wall, a cellular colony, which frequently 
breaks away and is able to lead a separate existence. It is indeed 
the fresh-water species of Endoderma which have this tendency 
developed to the greatest extent. 
The regular rounded shape, either ellipsoid, spherical or ovoid, 
of the cell in the young vegetative filament of E. Cladophorce before 
the production of a thallus or penetration of the cell-wall of the 
host, is characteristic of this species. In all the other species, with 
the exception of E. Pithophorce, which is further characterised by 
its filaments never anastomosing, the cells are very irregular and 
are often curiously elongated. 
At present E. Pithophorce seems to occupy a place by itself 
in this genus, but E. polymorpha and E. Cladophorce connect up the 
sections “ Entocladia” and “ Ectochcete ” of the genus Endoderma. 
Diagnosis :— ENDODERMA CLADOPHORJE nov. sp. 
E. epiphyticum et endophyticum; filis subbrevibus, irregulariter 
subramosis, ramis plerumque concretis paullo attenuatis; cellulis 
magnis, ovoideis vel ellipsoideis, demuin e mutua pressione 
angularibus, chromatophoro singulo parietali irregulariter lobato, 
pyrenoide singulo (rarissime binis) praedito. 
Long, thalli usque ad 480/t; diam. cell. 6-17*5/x; diam. cell 
in parte apic. ram. 3-5-4/x. Habitat in ramis Cladophorce rarius in 
filis Rhizoclonii, Rowton’s Well, Sutton Park, Warwickshire. 
My thanks are due to Professor G. S. West for the supervision 
and assistance given in this work. 
Botanical Laboratory, 
The University, Birmingham. 
’ G. S. West. West Indian Freshwater Algx, Jour. Hot. Vol. XLII, 1904. 
