TREE TII abe ody ek 
aan 
MR. G. MURRAY ON BOODLEA. 245 
hesitation in assigning it. If we start from Cladophora in the 
direction of Spongocladia, it I may so express myself, we find in 
the latter genus occasional tenacula, which, however, do not 
serve to unite the filaments into any definite reticulate frond, 
but are more probably of use in binding them together in 
strands. Spongocladia is at once very like Cladophora ; and, as 
regards its long filaments, which are septate only in the basal 
region, not unlike Vaucheria, for example. Let us take Boodlea 
next. It retains the resemblance to Cladophora in its jointed 
filaments; but the tenaeula are very abundant and unite the 
filaments in the fashion just described. In Microdictyon we have 
a further approach to the formation of a frond, since the adhesion 
of the filaments lying in one plane constitutes a true reticulum. 
In Struvea there is not only a definite and very beautiful frond 
(the adhesion still being by means of tenacula), but a stalk, the 
structure of which indicates relationship with Valonia. Before 
coming to Valonia, however, we have two genera, Apjohnia and 
Chamedoris, with the Valonia-like stalk-structure, but with fronds 
which are no longer held together by tenacula, but wave free in 
the water. From these to Valonia it is but a step. I may 
therefore claim for Boodlea that it forms a very important link 
in establishing a connexion between the Siphone: (sens Agardh) 
and the jointed green Alge. It thus strengthens the cohesion 
of the group of Siphonocladacee, or, at all events, of that portion 
of the group which everybody accepts. 
Booprra, nov. gen., G. Murr. et De Toni. 
Alga viridis, marina, spongiosa, aspectá frondis defecta, ex filis 
confervoideis regulariter articulatis, iterum atque iterum ramosis, 
quocunque vergentibus, inter se per tenacula adherentibus 
composita. 
B. coacta, n. sp. Pusilla, coacta, cellulis eylindrieis diametro 
2-10plo longioribus; ramulis aut singulis aut binis, hinc illine 
inter se per tenacula adheerentibus. 
Syn. Cladophora coacta, Dickie (Journ. Linn. Soc., Bot. xv. 
p. 451). 
Hab. Ad Osima Harbour, Nippon, Japan, ‘ Challenger’ | et ad 
ins. Mangaia, in oceano Pacifico lat. 21°57’ S., long. 158" W., Gill! 
(sub nomine Microdictyi Montagnei, Harv., in Dickie, * Algz from 
Mangaia," Journ. Linn. Soc., Bot. xv. p. 33). 
T2 
