242 
Two of the original specimens collected by Lyall are preserved 
at Kew, and they clearly show that on this occasion Agardh was in 
error and that the plant is a Mitophyllum. 
Though nearly allied to WV. palmata, the present plant appears 
to be distinct from any of the species described in that difficult 
section. The root-like processes, with which both the surface and 
margin of the frond are beset, give the plant a peculiar appearance, 
but as these bodies are not always present this character must be 
used with care. In Britain similar outgrowths are met with upon 
certain forms of NV. laceratum, especially those in which procumbent 
fronds are present, or those in which the fronds are in contact with 
other algae. The stimulus of contact appears in this species to be 
capable of bringing about the production of these peculiar 
attachment organs. rom the appearance of the Kew speci- 
mens of NV. variolosum it seems very probable that the same cause 
might occasion the formation of root-like processes in that species. 
Harvey’s diagnosis precisely describes the Kew specimens an 
nothing of material importance can be added to it. 
As surmised by Agardh, C. apiculifera was not unknown to 
Harvey, but he regarded it as a Callophyllis, having named it, as 
shown above, C. asperata. The ciliate processes on that plant bear 
no resemblance to those on the Nitophyllum, but are densely 
scattered over both surfaces of the fronds and have not the slightest 
appearance of being organs of attachment. 
Nitophyllum uncinatum, ./. Aqg., Species Alg., vol. ii., p. 654 
(1852), 
Nitophyllum uncinatum is a very distinct species, but it is one 
which has become obscured owing to the fact that uncinate branches 
may be also produced by other species of the genus. 
The plant was first described by J. Agardh in 1852. He states 
that it is not uncommon in the Mediterranean, and was characterised — 
by the possession of acuminate fronds and of occasional uncinate 
branches ; the sori moreover were produced immediately behind the 
apex of special short branches. Unfortunately, Agardh quoted as 
a synonym JN, laceratum var. uncinatum, Grev. The latter is 4 
perfectly distinct plant, but the error has been perpetuated. 
NV. laceratum, Grev. assumes a large number of forms and the 
variety uncinatum, Grev., is not at all uncommon in the south of 
Eng and. In the tetrasporic condition there is no difficulty in 
separating it from Agardh’s species, and even when sterile, the 
straggling habit, the dingy colour, the blunt apices of the frond an 
well-marked veins are usually sufficient to distinguish it. +4 
Britain N. uncinatum, J. Ag., is very rare and UN. laceratum vat 
uncinatum, Grev., is not uncommon, whilst in the Mediterranean the 
" reverse is the case, 
hen an examination is made of the Australian and New Zealand 
Specimens of Mitophylla a similar state of affairs is found to exist, 
two distinet species having been referred to N. uncinatum, J. Ag: 
One 18 a plant which with little doubt is Agardh’s species, and the 
other is an uncinate form of N. multipartitum H. and H.. The 
former agrees in form and structure with the European specimens; 
but up till the present it has only been examined in a sterile state. 
