48 Psyche [April 



the small black bristles of the front coxse; while they are somewhat 

 inconstant, they yield some good distinguishing marks. The 

 front femora have on the under side some short stiff spines, against 

 which the tibia closes with its row of spinules, thus holding the 

 prey while it is devoured. This arrangement is repeated in many 

 slightly varying forms in the different species, but in three, cane- 

 scens, amplectens and breviseta, a secondary modification has taken 

 place in the male, furnishing special grasping organs which must 

 be for the purpose of holding the female, since they are confined 

 to the male sex; in amplectens it is a question if the second func- 

 tion has not superseded the first. The middle and hind legs 

 offer a few slight and one (breviseta) rather striking ornamental 

 or other male characters. 



In the measurements I have included the length of the wing, 

 as the abdomen shrivels to such a variable extent that the length 

 of the body becomes untrustworthy except in a general way. 



Table of Species. 



1. Knobs of halteres yellow 2 



Knobs of halteres inf uscated, at least on outer side 13 



2. Postvertical bristles in a row of six or more (fig. 4) 5 



Postverticals only two as usual 



3. Scutellar bristles one pair. . . . .' gratiosus sp. nov. 



Scutellar bristles more than two pairs 4 



4. Propleural bristles several plumbeus sp. nov. 



Propleural bristles (black) none or only one intentus sp. nov. 



5. Propleural one 8 



Propleural none 6 



6. Second longitudinal very short, ending opposite hind crossvein 



(fig. l) cerutias Loew. 



Second vein normal, much longer (figs. 2, 3) 7 



7. Dorsocentrals minute, white canescens Wheeler. 



Dorsocentrals small, black agalma Wheeler. 



8. Face opaque non-metallic aestuum Loew. 



Metallic color visible on upper part of face 9 



9. Tip of front tibia in both sexes with an acute angle produced toward 



the femur (one to three bristles on upper outer corner of front 

 coxa, and the face generally very bright blue-green as far down 



as the suture) philombrius Wheeler. 



Tip of fore tibia not or but slightly angulated toward the femur 

 (face not shining so far down, generally no bristles on basal part 

 of front coxa) 10 



10. Front tibia of male notched on inner side at two-thirds its length 



