University of Michigan 



PLATE I 



Figures 1-4. Wing photographs. Fig i, Ischnogoinphus jcssci,. 

 type male; 2, Cyanogoiiiphits tuiiicns, type female; 3, Erpetogouiphus 

 sabaleticus, type male; 4, Erpetogouiphus crotalinns, male, Durango, 

 Mexico, Biol. Cent. Am., p. 165. ^lagnification in fig. 2 greater than in 

 the others, where it is equal. 



Notice the slender abdomens of Ischiiogouphus Jcssci and Cyano- 

 gomphus tiimens as compared with Erpctogomphns sabaleticus. The 

 male of C. tiimens is doubtless more slender than the female figured. 



Figures i, 3 and 4. photographs by C. H. Kennedy, Department of 

 Entomology, Cornell University ; fig. 2 from Dr. Calvert. 



