ON THE BLOOD-LIKE PHENOMENA. 
107 
On the following day I had leisure microscopically to examine and 
delineate the fresh plants which I collected from the originals, and 
will publish in the Symboli Physici. The Thelephora sanguinea, 
which is accurately distinguished from the other Thelephorae as a 
Palmella, but has been inaccurately placed among the Algee, is dis¬ 
tinguished by a real peridium (a firm epidermis) which is entirely 
wanting in the Egyptian form, which consequently appeared to be of 
a gelatinous nature. I have described it as a particular genus, and 
called it Sarcoderma sanguinea. 
Sarcoderma.— Char. Gen. Thallus gelatinosus rugulosus granulis 
discretis repletus nec fibrous nec epidermide (peridis) instructus. 
The Nostocinen Algee have a peridium. 
Another kind, the Geocharis nilotica, rather of a cinnabar than a 
hlood-red, though of a very lively colour, is universally prevalent in 
Eygpt, on the wet banks of the Nile, where Riccia glauca grows. 
It is a very remarkable kind of small mushroom, having a very close 
affinity to the Vaucheria granulata of Lyngby, or the V. radicata of 
Agardh; but, notwithstanding this, it certainly belongs to the fungi 
and not to the algge. 
Geocharis. Char. gen. Thallus tubulosus continuus teres filiformis 
(radiciformis). Vesiculse fructus externae inflatae (Coniocystae) spo- 
rangiis, sporangiis sporidia colorata incluudentibus repletae. 
In the same year, I found at Siut in Upper Egypt, after the inun¬ 
dation of the Nile, a stagnant water of a very red colour. The colour¬ 
ing body was the Sphaeroplea annulina of Agardh, a well-known 
algo of fresh water. 
In 1823,1 was for a number of months at Tor, on the Red Sea, in 
the vicinity of Mount Sinai. On the 10th of December I there 
observed the striking phenomenon of the whole bay, which forms the 
harbour of Tor, of a bloody colour. The main sea beyond the coral 
reef that encloses the harbour, was as usual colourless. The short 
waves of the calm sea during sunshine, carried to the shore a blood- 
coloured slimy mass, which it deposited on the sands, so that the 
whole hay, fully half a league in length at the ebb of the tide, ex¬ 
hibited a blood red border of more than a foot broad: I took up some 
of the water itself with glasses, and carried it to my tent at hand on 
the sea-shore. It was immediately discovered that the colouring was 
caused by small flakes scarcely distinguishable, often greenish, some¬ 
times of a lively green, but for the most part of a dark-red colour, 
although the water itself was not stained by them. This very interest¬ 
ing appearance attracted my attention as explanatory of the name of 
the Red Sea, a name hitherto so difficult of explanation. I for 
K 3 
