No. 6. — Results of the Yale Peruvian Expedition of 1911. — The 

 , Arachnida. 



By Ralph V. Chamberlin. 



The arachnids, upon a study of which this paper is based, were 

 collected for the most part by Prof. H. W. Foote while a member of 

 the Yale Peruvian Expedition of 1911. The collection has proved to 

 be extraordinarily interesting, presenting a very large proportion of 

 previously undescribed forms among which are eighty -two new species 

 and twelve new genera. A few specimens were secured at Panama; 

 but aside from these, the material all comes from localities in a little 

 known section of southeastern Peru at elevations ranging from 3,000 

 to 11,500 feet above sea level. Comparatively few of the species 

 seem to be identical with forms recorded from more northerly locali- 

 ties of Peru by Taczanowski in his Les Araneides du Peru (Bull. Soc. 

 nat. Mosc. 1878, 53, p. 278-374; Horae Soc. entom. Ross., 1878, 14. 

 p. 140-175; 1879, 15, p. 102-136). Some of the localities mentioned 

 are not on published maps. 



This collection of arachnids was turned over to the author for study 

 through the kindness of Professor Foote, who has also consented that 

 the entire lot remain the property of the Museum of Comparative 

 Zoology. Prof. A. Petrunkevitch of Yale had planned to report 

 upon the collection but the press of other duties prevented. He had 

 made notes and drawings of several species which were kindly sent 

 to me. 



The principal Peruvian localities from which the arachnids of the 

 collection come with elevations and months during which specimens 

 were secured are as follows : — 



