HESPERAGRION 303 
dorsal stripe by a pale area. Sides of the thorax pale with a short dark spot on 
the upper end of the second and third lateral sutures. Legs mostly pale. Stigma 
with the proximal end tending to be more oblique than the distal end so that the 
costal side is shorter than the posterior. 9-10 postnodal cross veins in the fore 
heterodoxum 

minutum 
wing, 8 in the hind. Dorsum of abdominal segments 1-8 brassy black with pale 
interrupted basal rings on 3-8; 9-10 usually entirely blue, 9 sometimes with a 
dorsal black spot. 
Female.—Similar to the male in all respects except the hind margin of the 
prothorax is deeply trilobed, the dorsum of abdominal segment 9 is entirely 
brassy black, and there is a well developed ventral spine on 8. 
Nymph—unknown. 
65. HESPERAGRION Calvert 
These are small, brilliantly colored Sonoran damselflies that are 
found only on our sothern border. The abdomen is moderately slender, 
slightly widened at both ends. The wings have arather long quadrangle 
and a short stigma that is wider on its posterior than on its anterior 
side. The stripings of the thorax and the pattern of the abdomen show 
a remarkable variation of very brilliant colors; the changes are appar- 
ently due to age. 
The nymph of this genus was reared by Mr. Frank C. Willard near 
Tombstone, Arizona, and described by the senior author (Ndm. ’04, 
p. 717). “The situation was a deep reservoir of cold water, formed by 
damming a stream that flowed through a narrow canyon. The imagoes 
of the species ‘spent most of their time among the joint-grass that grew 
in the edge of the water.’ ”’ 
294. Hesperagrion heterodoxum Selys 
Selys 68, p. 69: Mtk. Cat. p. 53. 
Syn: flavescens Selys 
Length 28 mm. Expanse 36 mm. Ariz. 
This pretty species is remarkable for its extraordinary range of color. Changes 
that seem to be due to age range from a pale yellow thorax without stripes, 
through red with a middle bronze stripe, to blue with an antehumeral black 
stripe each side of the front; from plain yellow on the top of the head, through 
blue with red postocular spots, to wholly black; from pale abdomen with middle 
