294 



C. SKOTTSBKRG 



and penguins arc occasionally seen around the islands but do not breed 

 there. 



Of the i; s{)ecies l)reedin<^ on the islands 3 are endemic; of the remaining 

 12, 6 are re|)resented b\- endemic subs|)ecies of which, however, 2 also breed on 

 the Desventuradas Islands. Including these, 60 % of the birds are endemic, a high 

 figure in animals as mobile as birds are. Otherwise, the poverty of the island ornis 

 is noteworth}-, as also the fact that the affinities of the landbirds are all with 

 S. America. 



With regard to the actual distribution we can distinguish the following two 

 groups. 



I. South American (especially Chilean) group. — 10 sj). 



a. luulcmic (6): Anaeretes fernandczianus, Aphrastura masafuerae, Euste- 

 phanus fernandcnsis, Cinclodes oustaleti baeckstroemii, Cercneis sparverius fer- 

 nandcnsis, lUitco erythronotus exsul. 



/>. Not endemic (4): Turdus magellanicus, luistephanus galeritus, Asio flam- 

 meus, Pufhnus creatopus. 



II. South Pacific group. — 5 sp. 



a. l^ndemic (3): Pterodroma externa externa, cooki defilippiana and cooki 

 masafuerae. 



i). Xot endemic (2): Fregetta grallaria, Pterodroma neglecta. 



The fust grouj) includes of more tropical birds jhiaeretcs, Cinclodes and Eu- 

 stiphaiius, and of more temperate Turdus, Asio, CevcJuieis, Buteo and Puffiuus. 

 Of the endemic species luistepliauus fernandcnsis is the most notable, in certain 

 characters a unicpie t}'pe in the family Trochilidae. The second group is of par- 

 ticular interest as including, beside the widespread frigate-bird, four species of 

 Plcrodroina not breeding on the mainland, where, perhaps, a special race of 

 /'. cooki breeds. The genus is essentially austral-circumpolar, as it were tricentric, 

 w ith Tristan da Ounha representing the African sector. Cases like those of /^. neglecta 

 and externa call for a common source and suggest that Pterodroma belongs to 

 an Antarcto tertiary element which inhabited the coasts and islands of Antarctica 

 n prjglacia! timjs. 



Oligochaeta. 



Mich Al.l.sKx (/<S7) regards all the earth-worms of Juan Fernandez as adven- 

 titious. The single strictly South American Kerria saltensis was, he believes, in- 

 troduced from Chile with the human traffic, and this is also true of the three species 

 of Allolobof^hora, introduced to Chile from luirope, and by Friedericia galha. The 

 occurrence ot I\uhydrihis rcrrucosus offers more interest. It was known from Great 

 Ikitain, the Hebrides, S.W. Africa and h'uegia, everywhere living on the seashore; 

 on Masatierra it was not found on the beach but inland in a freshwater stream. 



Hirudinea. 



The leech discovered in 19 17 in the highland of Masafuera was described 

 as a new species of the Australian genus Pliilaenion, Ph. skottsbergi L. Joh, [147). 



