CHLOROSPERME®. 19 
rocks, while C. lanosa, of a similar size, is usually parasitic on other alge, 
as already described. C. glaucescens is a beautiful species, occasionally 
reflecting glaucous tints, as referred to in its specificname. C. Gattye, 
Macallana, Brown, and 
two or three others, com- 
plete the list of British 
species of this genus. 
| The curious genus 
| Codium contains some 
| very remarkable species, 
two of which, except that 
they grow generally in 
masses on the surface of 
rocks, rarely attract the 
attention of ordinary col- 
lectors, and are certainly 
not common; but there 
is one species which is 
among the most singular 
of seaweeds, and that is 
Codium bursa, the Purse- 
like Codium. This plant 
is very rare; but, as col- 
lectors may unexpectedly 
meet with it, some little 
description of the curi- 
osity may not be amiss. 
Its habitat or place of 
growth is on rocks, near 
| low water mark, and its 
appearance is that of a 
round hollow’ spongy 
ball, from one to several 
inches in diameter. The 
whole plant is made up 
of a very closely inter- 
woven mass of tubular 
filaments, giving to the 
plant the appearance of 
a round green sponge. Many years ago I used to find this very rare 
and curious species growing on one rock only, at the very verge of 
low water between Brighton and Rotting Dene, and but that the 
little ‘‘ mermaid’s balloons,’’ as I once heard them called, were green, 
one might liken them to the well-known puff-balls of the field. The 
species most commonly met with is C. tomentosum (Fig. 22). This 
plant is also singularly like one of the branching sponges. The stem 
Fig. 21. Branchlets of Cladophora. 
