X te collection of spiders that this paper will give an account 

 of, is brought together by oiie of our most distinguished tra- 

 vellers and investigators, Mr P. Dusen, in the valley of Rio 

 Aysen in the sonth of Chile. Besides his botanical and geo- 

 logical researches he collected a great number of spiders, a 

 great deal of which, however, are young animals and on that 

 account indeterminable. This collection has Professor Chr. 

 AuRiviLLius, Intendent of the Entom. Dep. of the Royal Mu- 

 seum in Stockholm, kindly committed to me for working. 



As it appears from the systematical list, there are 39 

 species, 24 of which, as I believe, are new to seience. Among 

 the new species tvvo represent each its new genus. 



The species known before, as far as we know, generally 

 have a very limited geographical distribution. Of the family 

 Theridiidse I have noted Theriäium gracile Keys, before found 

 only in Chile, and Theriäium spirale Em., that, however, I 

 cannot with certaint}^ say l^eing surely determinated, before 

 collected on several localities in the United States and in 

 Venezuela. Ulescmis scutula (Nic.) is indigenous in Chile. 

 Of the family Argiopidc© the collection contains only one 

 species known before. That one, Araneus flaviventris (Nic), 

 is spread vastly towards the south and is found on Tierra 

 del Fuego. Of the genus Grnolus the collection contains five 

 species, three of them found before viz. Gnolus spiculator 

 (Nic), cordiformis (Nic.) and angulifrons Sim. These species 

 are for the present found only in Chile. Even the exclusively 

 chilian species Oarces recticulatus (Nic.) is found by Mr Dusen. 

 To the family Thomisidt© belongs Stephanopsis ditissima (Nic.) 

 even distributed to Tierra del Fuego. Of the family Clu- 

 bionidse Äporatea valdiviensis Sim. and Mezenia dorsalis Sim. 

 are exclusively chilian species, but Gayenna immanis (Sim.), 

 varia (Sim.) and affinis Tullgr. are found even in the south 



