686 C. SKOTTSBERO 



Group 6. West Indian. — i sp. 

 Chantransia CoUinsiana. ^ 



Group y. Subantarctic (Antarctic)-circumpolai'. — 4 sp. = 4 %. 



Geminocarpus gem'matiis, Phycodrys querdfolia , Sc/iizoseris Davisii, Polys'iphouia 

 abscissa (north to Peru). 



Group 8. Endemic. — 32 sp. = 34 ^'2 %• 



To utilize fully the endemic species for a discussion on the history of the 

 flora, we must know their systematic position within the genera to which they 

 belong. As it is, little is known about the genetic relation, in most cases at 

 least. Therefore we have to confine ourselves to a subdivision according the 

 general distribution of the genera. 



a. Widely distributed, in cases subcosmopolitan genera, not exclusively or 

 mainly found in warmer seas. — 7 sp. 



Cladophora perpusilla, Edochaete pacijica, E. raiiwsa, Ectocarpus uuiiutissimus, 

 Chautransia ferna?tdeziaua, Ch. grandis, Atitithamnion uiuuitissimum. 



h. Genera with a +. wide distribution in warmer seas. — 22 sp. 



Chaetomorpha firma, Codium cercbriforme, C. fernandezianum, Didyota phlyctaenodes, 

 Pad'ma fernandeziana, Liagora brachydada, Gelidium pseudoi?ifrica/umi^:), Gratcloupia 

 stibsimpkx, Cryptonemia proUfera, Nemastoma foliaceum, Botryodadia fernandeziana, 

 Pleonosporium globuliferum , Pterosiphonia pusilla, P. Skottsbergii, P. disticha, Stromato- 

 carpus microscopicus, Dipterosiphonia parva. To this group I attach Halicystis pyri- 

 formis (3 Atlantic species, one of these also on the Pacific coast of N. Amer.), Dislro- 

 mium Skottsbergii (a second species from Japan), Papenfussiel/a Moseleyi (most species 

 South African), and the two endemic genera Chondriella ( i sp.) and Fer7iandosiphonia 

 (i sp.). 



c. Genera with their main centre in Australian waters. — 3 sp. 



Gloiflderma suhdichotoiiuiin, Hypoglossiim parvuhim, Hyineucna decumbens. 



We can disregard groups i and 8 a, which, with our present knowledge, 

 cannot tell us anything about their history. Taking together groups 3 and 4 

 we get a West American group of 14 species (= 15 %), a remarkably small 

 number. Even if future researches will add to this group we have little reason 

 to believe that the proportion between this element and the non-American will 

 undergo much change. 



Group 2, 13 sp. (= 14 %) is of a more or less distinctly subtropical char- 

 acter, and the same may be said of group 8 b, 22 sp. (23% %), and of group 5, 

 although Splaclmidiuni with its obligate parasite reaches the cool waters of New 

 Zealand. I think we can bring together all three to constitute a Subtropical 

 element, 54 species, or 58 %, which may be said to give the Juan Fernandez 

 flora its special characteristic features. We have seen that a Subtropical element 



' Gdididla sp. is perhaps identical with a West Indian species 'Lkvring p. 636 . We 

 cannot draw any conclusions from our present knowledj.;e of the distrilxuion of microepiphytes 

 like Ectocarpus pusillus or species of C/iuutransia, etc., which are likely to have been over- 

 looked especially in regions where little collecting has been done. 



