Pref 



ace 



University, whose liberal grants for the purchase of books and of 

 specimens have made possible the prosecution of my studies in 

 a satisfactory manner. 



Important aid has been rendered by several specialists. 

 Mr. Peckham has determined specifically a considerable part of 

 the large collection of Attidae in the Cornell University museum. 

 Mr. Emerton has also determined many species of spiders. And 

 Mr. Banks has rendered assistance frequently throughout the 

 preparation of the work in the determination of both spiders and 

 other arachnids. 



Several students, who have worked under my direction, 

 have contributed in an important way to the advancement of the 

 work; notably Prof. R. V. Chamberlin, by studies of the Lycosidae; 

 Prof. C. R. Crosby, by studies of the Erigoninae; Miss Effie 

 A. Read, by help in the preparation of the key to the genera of 

 the Attidae; Mr. R. A. Cushman, by studies of the external 

 reproductive organs of the Argiopidae; Dr. J. A. Nelson, by the 

 preparation of many palpi of male spiders; and Mr. J. T. Lloyd, 

 by testing and suggesting changes in some of the analytical 

 keys. 



Early in the progress of the work on this book I had the good 

 fortune to secure, by purchase for Cornell University, the col- 

 lection of Dr. William H. Fox of Washington. This contained 

 nearly 250 named species of spiders; and as the identification of 

 the specimens had been confirmed by the late Dr. George Marx, 

 the collection formed a very important addition to the Cornell 

 University museum. And I am indebted to Doctor Fox for in- 

 formation regarding certain specimens in the collection made 

 by him. 



Contributions of specimens have been received from many 

 persons; and large numbers of specimens have been received from 

 each of the following: Prof. C. R. Crosby, Mr. Paul Hayhurst, 

 and Dr. J. A. Nelson. 



To Dr. B. G. Wilder I am indebted for my first interest 

 in spiders, acquired during my undergraduate days, and for 

 placing at my disposal, in later years, all of his notes on spiders. 



The photographs from which a large part of the illustrations 

 were made were taken by myself, except in those cases where 

 credit to others is given. Some of the drawings, especially 

 those in the chapter on external anatomy, excepting those of 



viii 



