A key to the genera and subordinate groups of Urocoptida, 

 with a general discussion of the affinities and distribution of 

 the family, will form the Introduction to Vol. XVI, the first 

 two parts of which will contain monographs of the remaining 

 genera, and an Index. 



I am deeply indebted to Mr. JOHN B. HENDERSON, Jr., of 

 Washington, D. C., for the use of his very large series of 

 Jamaican and Haitian Urocoptida, and to Mr. P. W. JARVIS, 

 of Kingston, Jamaica, who supplied me with many specimens 

 and valuable notes, and with maps showing the distribution 

 of Jamaican species. Messrs. SOWERBY and FULTON also have 

 courteously supplied information upon particular species de- 

 scribed by the former; and for still further information and 

 specimens I have to thank my friends Dr. WM. H. DALL, of 

 the National Museum, and Mr. GEO. H. CLAPP, of Pittsburg. 



(v) 



