124 МВ. Н. N. RIDLEY ON THE WEST-AFRICAN 
nando Noronha to afford resting-places, would probably suffice to explain the similarity | 
that exists. Now though this might be sufficient as regards the insects, possessed as they 
are with means of flight, it cannot be considered satisfactory in the case of these Cypera- 
ceous plants. They have no means of transmission, nor are they plants likely to have 
been introduced by man; and further, if the list given above be examined, they will be 
found to be almost entirely forest-loving plants, of all plants the least likely to be 
drifted across the ocean by currents. 
Th. Studer, in $ Beiträge zur Meeres Fauna von W. Afrika,’ in comparing the marine 
animals of the west coast of Africa with those of South America, states that out of 
20 species of Echinodermata collected in Africa, 17,—of 277 species of fish, 55,—and of 
541 Gasteropoda, 54 occurred on the American coast also. To account for this, he 
suggests that the young of these animals may have been carried across the sea by 
currents, and cites the case of the Sargassum of Florida being drifted across to the Cape 
Verd Islands. ‘This is possibly the cause; yet it is singular that the largest proportion 
of species common to the two coasts, 85 per cent., is to be found in the Echinodermata, 
the oldest group of the three, and at the same time one that seems least able to make its 
way across the ocean; while in the later-developed Fish, which have far greater facilities 
for crossing the ocean, only 20, and of Gasteropods, whose eggs are frequently attached to 
seaweed and other floating objects, and might so get across, only 10 per cent. are common 
to both coasts. Now taking these facts into consideration, and remembering also that 
the insects, which Wallace admits have a certain number of species in common on 
both coasts, are an order of very great antiquity, it seems to be very probable that 
there was at some time in the world's history a complete connexion between Aírica 
and South America, at about which time Africa was also connected with Madagascar, 
and that the Cyperacez above mentioned are the relics of the flora of that period. 
It may be premature to endeavour to assign a date to this flora ; but it is probable 
that it existed prior to the Miocene period, since Wallace, 2. c., has shown from the 
distribution of the Mammalia, that there was no connexion between the two continents 
since the incursion into Africa of the large Carnivora, which took place in all probability 
in Miocene times; on the other hand, since there is no genus of mammalia common to 
the two continents except the aquatic Manatus, it was probably a great deal earlier. 
The Сурегасеге are but little used by the natives of Lower Guinea in medicine or the 
arts. The Papyrus, according to Dr. Welwitsch, is put to a variety of uses, such as to 
make paper, beds, for thatching, and even for bridges. The rhizome of Cyperus 
articulatus, L., is used in medicine for allaying intestinal pains, and seems to be cultivated 
to some extent for that purpose. In Ashantee, according to Mr. Teddie, it is used as an 
anthelmintic. С. Ayleus, an undescribed species, is used also by the natives in medicine; 
but for what diseases Dr. Welwitsch does not state. The tubers of C. rotundus and 
C. esculentus, L., though both common plants, do not appear to be used for food as they 
are in Damara Land and elsewhere in Africa. 
