KELLICOTT. 109 



Diplax assimilata, Uhler. 



Length: of abdomen d* 24-25, ? 22-25; hind wing 

 d" 26-29, 9 26-30. 



This and the above species vary considerably in 

 size, and one would expect to find specimens both 

 larger and smaller than the measurements given. 



D. assimilata has been placed as a synonym of 

 ruhicundula by Calvert, but by others it is considered a 

 distinct species. After a careful study of the anatomy 

 of both, I am unable to give any constant character 

 for their separation except the yellowish coloring of 

 the basal half of the wings in assimilata. 



Toledo July 30, Sandusky July 20, not uncommon 

 at Columbus. 



Dipiax obtrusa, Hagen. 



Length of abdomen d" 22-25, 9 24 ; hind wing d 

 22-25, 9 23-25. 



This species resembles ruhicundula so much that it 

 seems best to give simply the points of difference 

 between the two species. 



Genital hamules of the male with apical fourth 

 bifid, the branches of the same length; posterior 

 branch at least four times as wide as the internal 

 branch. 



The female is separated from the female of 

 ruhicundula by the vulvar lamina. In the last named 

 species this is short, rather broad and bifid at the tip. 

 The two lobes have the appearance of being inflated, 

 are strongly convex below, and straight above and 

 terminate rather abruptly ; while in obtrusa the 

 hamule, although short, and bifid at the apex, is 

 narrower, the two lobes have an angular appearance, 

 are only slightly convex below, and each sloper; rather 

 gradually to an acute point at apex. Instead of ap- 

 pearing inflated, the two lobes rather appear 

 contracted. 



