Sphaerococcus coronopifolius, Stackh. 
BY 
T. JOHNSON, B.Sc. (London), 
University Scholar in Botany , Demonstrator of Botany in the Normal School 
of Science, Kensington. 
With Plate XVIII. 
Vegetative Thallus. 
T HE red sea- weed Sphaerococcus coronopifolius , Stackh., 
occurs, in England, along the south-west coast from the 
Isle of Wight to Land’s End, being found attached to rocks at 
extreme low-water and deeper levels, by means of a disc-like 
4 root,’ from which one to three main 4 stems’ arise. The main 
stem produces irregularly placed branches, from which very 
numerous short upwardly directed branchlets spring. These 
alternate or subdichotomously formed branchlets are flattened 
and relatively wide, and have the whole length of their two edges 
closely beset with small cylindrical filaments, often themselves 
slightly branched (Fig. 1). The whole plant may be a foot long, 
and as broad as it is long. Each cylindrical filament repeats on 
a smaller scale the structure of its parent branchlet, and this of 
its parent branch (Fig. 2). Running through the middle of the 
filament is a central axis consisting of a uniseriate row of large 
tubular cells in which the usual Floridean characters are well- 
marked. From the distal end of each joint-cell of this central 
axis two lateral uniseriate cellular branches are given off right 
and left, obliquely inclined in an upward direction to the 
surface of the thallus-filament. Each lateral cellular branch 
forms a number of short secondary lateral branches arranged 
at right angles to the surface of the thallus, and closely 
[Annals of Botany, Vol. II. No. VII, November 1888.] 
