VI BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



material in the present and in subsequent parts of this work as easily 

 accessible as possible, the sequence of orders continues to follow 

 Ridgway's plan, but the arrangement of families, genera, species, 

 and subspecies within each order is patterned to agree with that given 

 by Peters. Inasmuch as the present work, like Peters' Check List, 

 is a reference tool, not a book to be read from end to end, no outrage 

 upon truth is committed by this alteration. 



Herbert Friedmann. 



