PROCEEDINCS 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. IV, pp. 411-454. [Plates xxvi-xxvii.] August 20, 1902. 



PAPERS FROM THE HOPKINS STANFORD GALA- 

 PAGOS EXPEDITION, 1898-1899. 



VIII. 



ENTOMOLOGICAL RESULTS (7). 



SCHISTOCERCA, SPHINGONOTUS AND 

 HALMENUS. 



By Robert Evans Snodgrass. 



CONTENTS : 



Introduction 411 



Genus Schistoccrca — general remarks 412 



Races of Schistocerca 413 



Relationships and evolution of the races 415 



Detailed descriptions . . . 419 



Genus Sphittgonotus — general remarks 436 



Diagnoses of races 437 



Relationships of races 43S 



Detailed descriptions 439 



Genus Halmenus — general remarks 447 



Detailed descriptions 448 



INTRODUCTION. 



The collection on which this paper is based consists of 176 

 specimens of Schistocerca^ 124 specimens of Spkingonotus, and 

 17 specimens of Halmenus. Nearly all of these specimens 

 were killed in cyanide of potassium and are preserved on pins. 

 The paper was prepared under the supervision of Professor 

 Vernon L. Kellogg in the entomological laboratory at Stanford 

 University. 



Only one Galapagos species of Sphingonotus has hitherto 

 been described. This is S. fusco-irroratiis of St&l, who says 

 Proc. Wash. Acad. Sci., August, 1902. 411 



