THE EURYPTERIDA OF NEW YORK 7 
really great ; indeed they represent some thousands of specimens and it is quite 
within reason to say that no series of the Eurypterida of equal size and 
variety has ever before been assembled. It is quite as true that no equal 
area in the world has proved as fruitful in the quantity and diversity of 
these organisms as the State of New York. And through the courtesy of 
many correspondents and museums much material from outside of New 
York has been placed at the demands of this work: the species of the 
Kokomo waterlimes of Indiana; of the Cambric Strabops of Missouri; the 
Siluric Megalograptus of Ohio and the Carbonic Hastimima of Brazil and 
New Brunswick; in all, I believe, an unexampled array of these extinct 
arachnids. | 
The work of elaborating these earlier studies and expanding them 
into this fuller form has very largely depended on the aid of Dr Rudolf 
Ruedemann who has brought to the work keen analytical powers, a broad 
grasp of its problems and an enthusiastic assiduity. I fully realize and 
gladly express my obligation to this assistance and desire that the inter- 
ested reader accord to my coworker adequate acknowledgment of his 
efficient part in this work. . 
The treatise itself seems to carry its own justification; aside from the 
close analysis of structural details, there are chapters on ontogeny, phylo- 
geny, on life habits and conditions as well as on organization which, though 
probably not beyond criticism, are at least informing and constitute an 
advance of knowledge. 
To the following individuals and institutions the authors have been 
indebted for aid: 
The Buffalo Society of Natural Sciences, through its board of trustees 
and its superintendent, Mr Henry R. Howland 
The American Museum of Natural History, through Dr E. O. Hovey 
and the late Prof. R. P. Whitfield 
The United States National Museum, through Drs R. S. Bassler, 
E. O. Ulrich and David White | 
The Smithsonian Institution, through Secretary Charles D. Walcott 
