

Leading Articles in Volume XIII 



Class I, Hexapoda ; Order II, Coleoptera. 



Fall, H. C. , 



On the Affinities of the Genus Tachycellus, with Descrip- 

 tions of New Species from the Western United States. 169 



Powell, P. B., 



The Development of the Wings of Beetles, and Studies of 

 the Origin of the Wings of Insects .... 5 



Roberts, C. H., 



The Distinctive Characters of the Eastern Species of the 



Genera Dytiscus and Cvbister . . . .103 



SCHAEFFER, C. , 



Three New Species of the Genus Statira Latreille . .179 



WlCKHAM, H. F., 



The North American Species of Cotalpa . . . 1 



Class I, Hexapoda; Order IV, Diptera. 



COQUILLETT, D. W., 



New Nematocerous Diptera from North America . . 56 



Dyar, H. G., 



A Synoptic Table of North American Mosquito Larvae . 22 

 Brief Notes on Mosquito Larvae . ... . 26, 107 



Illustrations of the Abdominal Appendages of Certain 



Mosquitoes ....... 53, 185 



A New Mosquito . . . . . . .74 



Knap,, F., 



A Cheironomid Inhabitant of Sarracenia purpurea, Metri- 



ocnemus knabi Coq. ...... 69 



Swenk, M. FL, 



The North American Species of Cuterebra . . .181 



