folsom: mouth-pakts of orchesella cincta. 35 



pable of further modification in either the rnandibulate or suctorial 

 direction. Indeed, the latter modification has already occurred in the 

 Collemholan genus Neanura. 



In conclusiou, I desire to thank Mr. Samuel Henshaw, whose knowl- 

 edge of entomological literature has been of great service to me. I wish 

 to acknowledge my special indebtedness to Professor Mark ; for his careful 

 and kind supervision have been my greatest aid and encouragement. 



