105 
THE TYSON COLLECTION OF MARINE ALGAE 
I. orbitosa, Augustineae, Agathoicus, serratifolia, cordata, curvata, cornea, 
laminarioides, undulata, gigantea and insignis. The fronds are very 
variable in form and size, and we have not found it possible to dis- 
tinguish these. 
4. Gigartina radula, Ag. 
Pools and rock ledges, Table Bay; a smaller form also from 
Knysna. (Also Robben Island, Kalk Bay, Sea Point. Barton(i); 
and Camp’s Bay. Delf.) 
Nearly all the specimens are either sterile or carposporic fronds, 
but one tetrasporic frond also occurs. 
G. stiriata, J. Ag. 
Submerged rocks, Table Bay. (Also Kalk Bay, Sea Point, Cape 
Point, Cape Agulhas. Barton (1); and Camp’s Bay. Delf.) 
All the specimens appear to be sterile or carposporic. 
G. Burmanni, J. Ag. 
Submerged rocks, Table Bay. (Also Simon’s Bay, Sea Point. 
Barton (l); and also Three Anchor Bay, Hout Bay and Camp’s 
Bay. Delf.) 
G. fastigiata. 
Rock pools and ledges, Table Bay. The specimens show sterile, 
carposporic and tetrasporic plants. (Also Robben Island, Sea 
Point, Cape Point, Kalk Bay and Natal. Barton (l).) 
G. pistillata, (Gmel.) Stackh. 
Algoa Bay, Kowie. 
G. Teedii, Lam. 
Cape Morgan, Walfisch Bay. (Also Port Alfred. Barton(i).) 
G. insignis, Schmitz (syn. Irideae insignis, Endl. and Dies.). 
Deep water, Kowie. (Also Port Natal. Barton.) One specimen. 
G. Tysoni n. sp., Reinbold. 
Camp’s Bay, Sea Point, Three Anchor Bay. This is probably 
a deep water form as it has only been found as a 1 wash-up of 
occasional occurrence (Journ. Bot. June, 1912). 
Notes on the genus Gigartina. 
The species of Gigartina are very variable in form, and apparently 
hybridisation may occur between G. Teedii and G. pistillata (Barton, 
Journ. Bot. May and Nov. 1896). 
G. radula is very variable in size; the smaller sterile fronds aie 
sometimes inflated. In the herbarium specimens, this is indicated by 
a stuffing with cotton wool. We have only seen this in nature on blight 
warm days; examination of the inflated fronds suggests no sign of 
disease but rather an accumulation of gaseous products ol assimilation. 
Nearly all the material is carposporic, only two sheets showing spec i- 
mens with tetraspores. We have found both forms growing side by side 
