Calvert: Odonata of the Neotropical Region. 171 



the humeral suture and at the latter its outer edge bends outward 

 (laterad) and backward (caudad) almost at right angles, then again 

 downward (ventrad) and forward (cephalad) on the lower part of the 

 mesepimeron, continuing downward over the mesinfraepisternum. 

 These dark stripes (humeral and mid-dorsal) show a tendency to 

 become black along the middle line of each stripe leaving the edges 

 and extremities brown, and eventually probably become black through- 

 out. Sides of the thorax blue ; a short very fine brown or black line 

 on the upper end of the obsolete first lateral suture, a longer thicker 

 black line on the upper end of the second suture, in some continued 

 downward by a very fine line ; pectus blue. 



Abdominal segments i and 2 blue ; the intersegmental articulations of 

 1 and 2 and of 2 and 3, a square dorsal basal spot on 1, and an isolated 

 triangular dorsal spot with its anterior angle more or less truncated on 

 the middle of 2, black. Dorsum of 3-7 black, having a lanceolate form 

 on 3 and 4, narrower and more acutely pointed anteriorly on 3, and 

 markedly contracted at three-fourths or four-fifths of the length of the 

 segment, again widening to the hind end ; sides and a transverse basal 

 ring on 3-7 blue, blue decreasing in extent on each successive segment. 

 Segments 8-10 blue, hind margin of 10 very slightly excised and ele- 

 vated into a low process, the tip of which in rear view is rather rounded 

 than trungated. 



Superior appendages a little longer than 10, in dorsal view nearly 

 straight, somewhat divergent, each one rather narrow, its inner edge 

 straight, outer edge slightly convex, apex tapering, subacute ; the inner 

 basal process of each appendage corresponding to that of A. gracile is 

 present, but concealed under the hind margin of 10 ; in profile view 

 each appendage rapidly decreases in thickness in its basal half, its 

 upper edge slanting caudad and ventrad, its lower edge nearly hori- 

 zontal, distal half slenderer, of subuniform thickness, directed slightly 

 upward, apex subacute. Inferior appendages about two-fifths as long 

 as the superiors, appearing merely as small tubercles applied against 

 the lower surfaces of the superiors. Legs blue ; a superior band on the 

 femora, much of the tarsi, and, in some at least, the tibiae blackish 

 inferiorly. 



Wings clear, stigma rhomboidal, blackish, its costal edge more often 

 longer than the proximal or distal edges, but not infrequently equal in 

 length. Front wings with 10-11 postnodals, 11 more frequent; hind 

 wings with 8-10 postnodals, 9 most frequent; M 2 arising nearest the 

 fourth. 



