DERIVATION OF THE FLORA AND FAUNA 295 



W'hctlicr or not the two species described frcjm Samoa and Madagascar, respec- 

 tively, belong to Pliilaeiiioii remains to be settled. JoiIANSSON ex[)ressed some 

 doubts with regard to the position of the Juan Fernandez leech and after his death 

 the question was taken up by N\I1KI,IN who showed that it should form a se[)arate 

 genus, NcsophilacDioi [i88). With its allies it forms a small austral group, pos- 

 sibly of old Antarctic ancestry. It must, of course, have a host; it was found in 

 the extremely wet Dicksonia forest, where Pterodroma cooki masafuerae makes 

 its burrows, the only possible host existing here (see also 7^7. 442). Truly no 

 leech has been collected on the bird, but extremely few specimens of this ha\e 

 been taken care of and examined. 



Crustacea. 



Amphipoda {§6). 



Orchcstia chiltiisis (chiliensis) Milne-Edw. Both islands, terrestrial and found 

 from near the shore to almost 600 m altitude. It is a bicentric species, known 

 also from Chile and New Zealand. 



Isopoda (i"//). 

 Beside 3 cosmopolitan species 2 endemic ones have been found, both be- 

 longing to widespread genera, Ligia litiginosa and Philoscia mirifica, the latter 

 referred to a new subgenus. 



Arachnoidea. 

 Araneae (22). 

 I am indebted to Professor Alb. Tullgren, who supplied much information 

 on the distribution of the genera. Berlani) lists 24 species, of wliich 4 are cos- 

 mopolitan and also occur in Chile; of the remaining 20 one, belonging to the very 

 large and widely spread genus Aranens and perhaps new, was left unnamed. The 

 other 19 are enumerated below. Here as in the following -f signifies an endemic 

 species, + + an endemic genus. Mt = Masatierra, SC = Santa Clara, Mf = Masafuera. 



Ariadna maxima Nicolet. Chile. — Mt, Mf. The genus widely distributed 

 (N. and S. Amer., Afr., E. Ind., Australia). 



-I- Theridion Baeckstroemi Berl. — Mt. The genus is cosmopolitan. 



Th. gracile Keyserl. Chile.- — Mf. 



+ Lephthyphantes Fernandezi Berl. — Mf. A cosmopolitan genus, but only a 

 single species recorded for S. America (Patagonia). 



■vMacrargus pacificus Berl. — Mt. The genus is known from northern N. Amer- 

 ica and Europe, but TULLGREN (in litt.) doubts that it has a wide distribution 

 in America; thus, its appearance in Juan Fernandez is rather unexpected. 



+ yl/. anstralis Berl.— Mf. 



■^ Leptoyhopirum (.^) Platei Y. Cambr. — Mt. Doubtfully referred to this Eu- 

 ropean genus, from which it differs in certain characters: "I'epigyne est d'un type 

 tout a fait different" (22.430). 



+ Tmeticus Defoei Y . Cambr. — Mt. The genus used to be quoted from N. 

 America and Europe, but TULLGREN informed me that a great many species are 

 now referred to other genera. 



