244 MR. G. MURRAY ON BOODLEA. 
and are united by apical tenacula into a body which (when allowed 
to swell up in water) has a pulpy spongy texture, and is net-like 
in whatever section it may be viewed. No genus has been described 
which would serve for the reception of such an organism; and I 
therefore establish one, and, at the happy suggestion of Dr. De 
Toni, name it in honour of my friend Mr. Leonard Boodle, F.L.S., 
who has been my fellow-worker in three recent researches on the 
group to which it belongs, viz. on Spongocladia, on Struvea, and 
on Avrainvillea. 
The discovery of this form led me to look more closely into the 
forms of Microdictyon in the British Museum Herbarium; and I 
was at once struck with the appearance of specimens labelled 
M. Montagnei by Prof. Dickie, from the Island of Mangaia in the 
South Pacifie, and published as such in our Journal (vol. xv. 
p.33). Examination of it very speedily revealed the fact that it 
was even a finer specimen of Boodlea. It exhibited tenacula in 
great abundance and in perfect preservation. The accompanying 
figures have been drawn from this material. 
The apical tenacula adhere to whatever portion of the adjoining . 
filaments they may come in contact with; and since the branch- 
ing is by no means regular, either as to the number of filaments 
given off at a particular point or as to the degree of their diver- 
gence, a very irregular maze of joined and jointed filaments is the 
result. As a rule, however, either one or two branches are given 
off at the same place. The configuration of the meshes is further 
rendered irregular by the occurrence of tenacula, though rarely, 
at indefinite points on the walls of filaments, where no doubt they 
have been produced in response to the stimulus of contact with 
neighbouring branches. The ordinary tenacula which occur at 
the ends of branches are commonly single, but sometimes in pairs, 
an arrangement which holds good for Struvea as well. 
The filaments and their septation are very like those of. Clado- 
phora ; and since they also resemble Microdictyon, one is by no 
means astonished that Prof. Dickie has at different times placed 
this alga in both genera. The contents of the cells, so far as 
ean be judged with safety from the dried material, agree very 
well with what Schmitz has described as typical of Siphonocla- 
dacee. The chlorophyll grains are flat with polygonal outline 
and central clear spot—the pyrenoid—and occur in denser mass 
towards the free ends of the filaments. 
As regards the systematic position of Boodlea there need be no 
