320 ENTOMOLOGICAL NEWS. [July, 'l6 



dominal segment 10 not so elevated, superior appendages not 

 so high, and an additional black stripe on the second lateral 

 thoracic suture." Of the four related species of the gracilc 

 group considered in this paper, indefensum has the lowest 

 tenth abdominal segment, and the superior apical apex is 

 strikingly rounded as compared with the others. It will be in- 

 teresting to know the female of indefensum and to note what 

 modifications of the middorsal thoracic carina between the 

 mesepisternal fossae have taken place. May it not be expected 

 that here the carina will be indented rather than elevated as 

 it is in ascendens? In spite of its close resemblance to 

 gracile, I believe that this species offers no such difficulties as 

 kenncdii, since the appendages are strikingly different from 

 its closer allies. These differences, however, are concerned 

 with parts of inferior appendages which have received little 

 attention. In many genera of Agrionines the inner posterior 

 surface of the inferiors are variously modified, the most com- 

 mon form being a dorsally directed, acutely tipped, tubercle. 

 These parts are concealed in lateral views, and are incon- 

 spicuous and usually neglected in dorsal views. In kenncdii 

 and gracilc the inner face of each inferior appendage is pro- 

 duced in a great flattened, inward curved, obtuse tubercle ; in 

 indefensum this is reduced to a small inconspicuous promi- 

 nence ; the appearance in posterior view of the apex of the 

 abdomen of indefensum, as compared with gracile and ken- 

 nedii, has suggested the specific name (see figs. 7, 8 and 9, 

 Plate XVII). 



On February 16, my father and I collected near the canal 

 and government sawmill at Christianburg about a mile below 

 Wismar. A short distance above the sawmill a dressing room 

 for bathers is located. We collected in brush on the right 

 bank of the canal below this dressing room, and along a small 

 stream on the left side of the canal, parallel to and only a 

 short distance from it, in the brush. My notes fail to show 

 just where the two specimens of indefensum were collected. 



Acanthagrion adustum n. sp. (Plate XVII, figs. 1, 2, 10). 



Abdomen .$ 21-22.5, average 21.95, ? 21-22; hind wing $ 14-15, 

 average 14.75, ? 16. 



