104 Bulletin Wisconsin X at ural History Society. [Vol. 9, No. 3. 



Holotype male — C3 — Milwaukee Public Museum, allotype female 

 — C2 — and paratypes in coll. Calvert. 



The species is at once distinct from the others by the narrow 

 abdomen, the form of the appendages and the conspicuous spots 

 at each antenodal of the hind wings. I was greatly in doubt 

 whether to name this species or not ; yet, as will be later apparent, 

 it did not seem to belong to any of the forms listed. 



Tetragoneuria cynosura Say. 



$ . — Colors brown, yellow and black. 



Labrum and frons yellow, face with an olive band, the pile on 

 the frons black. Frons above showing- various degrees of a black 

 T-spot, from a mere indication of the black stem to the fullest develop- 

 ment of stem and cross piece, the latter then covering the entire width 

 of the frons. Usually, however, even in such cases where the stem 

 of the T-spot is rudimentary, there is a metallic glint in the median 

 frontal sulcus. Vertex and antennas black, head black behind. 



Thorax brownish yellow, humeral and lateral sutures with irregu- 

 lar spots of bright yellow. Usually the black stripes show but little 

 or no metallic glints, and then only in fully matured specimens ; 

 these metallic glints are confined, as a rule, to the latero-inferior 

 convex plates of the thorax though occasional specimens may have 

 the metallic glints farther up below the wings, in which case the 

 pile hides most of the iridiscence. In no case is the metallic reflec- 

 tion as bright as in petech talis ; the latter shows decidedly violet 

 reflections throughout the extent of the lateral stripes, while cynosura 

 may show dark blue reflections, which are confined to the lower 

 lateral ridge. 



Legs black, fore femora and bases of all legs, luteous. 

 Abdomen flattened, and therefore appearing shorter than stella 

 and petechial)*, usually constricted as segment 3 after a moderate 

 dilation of segments 2 and 3. Segments often "telescoped", a com- 

 parison is therefore uncertain. Yellow lateral stripes interrupted at 

 base and apex of segments, absent on 10. 



Appendages spatulate, an inferior angle at the basal third, a 

 lateral ridge continued for a short distance beyond the inferior angle. 

 Viewed from above the appendages divaricate. 



