8 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL.XX. 



single genus Melanoplus. The sexes are nearly equally divided, the 

 males forming about forty-six per cent of the whole. Thirty genera 

 (eighteen new) and two hundred and seven species (one hundred and 

 fifteen new) are described in the present paper. 



Finally, by the aid of a grant from the ELIZABETH THOMPSON SCI- 

 ENCE FUND I have been able to procure illustrations of the abdominal 

 appendages of every avaiable species. 



A few words should be added regarding certain details of presenta- 

 tion: Instead of giving the range of variation in the measurements of 

 each species, I have selected as far as possible typical average speci- 

 mens, male and female, for the purpose, taking the measurements of all 

 parts from the same individuals. The number of individuals of each 

 species seen is given, and the localities from which they came immedi- 

 ately added, with the name of the collector (when not myself), and 

 when not from my own collection, the source from which I have received 

 them stated (in parentheses); occasionally my own name is there 

 added, when specimens from the same source are also found in my col- 

 lection ; where no parenthesis follows the locality, the specimens referred 

 to are in my collection. 



In describing the abdominal appendages of the males, I have found 

 it convenient to introduce a few new terms. These are: Furcula for 

 the pair of backward-directed apophyses of the last dorsal segment, 

 which overlie, generally in a more or less forked position, the base of 

 the supraanal plate ; infracercal plates for the variously developed but 

 generally inconspicuous paired plates, which underlie in part the cerci, 

 in part the lateral portions of the supraanal plate; and. pallium for the 

 sometimes erectile, membranous pellicle partially closing the open 

 cavity formed of the walls of the subgenital plate, and variously devel- 

 oped in the different genera. 



December 20, 1895. 



NOTE. The exclamation point employed in the synonymy of the species has its usual 

 significance that the reference is authoritative from an examination of the original 

 types of the author in the passage referred to, with the present paper in view. 



