RHODOSPERME. 129 
But, as regards the species D. angustissima, I can only say, I have never 
met with it in the growing state; the only specimen I possess was given 
to me by the late Dr. Cocks, of Plymouth, who received it, with some 
_ others, from Mrs. Griffiths, of Torqray, that lady having found it in 
Torbay, about the time it was discovered by Mr. Brodie, more than fifty 
yearsago. The fructification of this rare plant seems to me to be identical 
with that of D. alata, and the only difference that I have been able to 
discover between it and the narrowest form of D. alata in my possession, 
is the extreme tenuity, or perhaps even the absence of the lateral membrane 
which is always present in the narrowest form of D. alata, var. angustis- 
sima. In Fig. 117, b, is represented an enlarged leaf of the pretty species . 
D. ruscifolia. The leaflet arising from the midrib shows the order of 
growth in this proliferous species, luxuriant specimens being like balls of 
Fie. 118. Delesseria hypoglossum. 
crimson leaves. This is the smallest of the genus, and though it is some- 
times found on the stems of Laminaria digitata (Fig. 46), its more frequent 
place of growth is on mud-covered rocks near low-water mark. Many 
years ago I used to take it in great quantity and beauty on the muddy 
rocks near Mount Batten at Plymouth. In our iliustration the coccidium, 
or spore-bearing tubercle, is represented (as is usual in the Delesseriv) as 
produced from the centre of the midrib, a short distance only below the 
tip of the leaf. Tetraspores are arranged in oblong groups on each side of 
the midrib, and generally near the tips of the rounded leaves of the plant. 
The colour is always a rich deep crimson, and with a little judicious 
pruning, this species makes an exquisite book specimen. The only British 
seaweed with which this species may be confounded is D. hypoglossum, 
represented at Fig. 118. In this, however, the fronds are longer and 
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