ARGIA 291 
13 Mesostigmal lamina prolonged at the mesal end in a slender 
POC ESSE Me ck ante eee Wem a cats Sasa ao wa ates eaten 14. 
Mesostigmal lamina rounded with no slender prolongation...... 
oe te SLO EMER EL OMMR at 208 Se eee Pei amne agrioides, p. 291 
14 Length of abdomen 20 mm. Mesostigmal lamina with a projection 
near the dorsal*carma: gs) ..2°S) 250% vest violacea, p. 300 
Length of abdomen 22 mm. Mesostigmal lamina without a pro- 
jection near the dorsal carina. California, Colorado and Utah 
ENA Ee oe Alc CTS Re es eee: alberta, p. 292 
fceeeed VU ANOS TINO NN eS har ete orzectgeriycdenc Ts GiiGrs Shee fumipennis, p. 295 
Weanesrcleaneron (ean. Agni te Moe, 2G ahd ake She 16. 
16 Black middorsal thoracic stripe a mere hair line. .apicalis, p. 292 
Black middorsal stripe at least one third as wide as the pale 
STLCMUMMEER ones Seer PR En ee ee ee) Cee ee AZ: 
17 Abdominal segments 2-3 mostly pale....... bipunctulata, p. 293 
Abdominal segments 2-3 mostly dark...................... 18. 
18 Mesepisternal tubercle well developed. Dorsum of abdominal seg- 
ments 8-9 pale with black markings......... translata, p. 300 
Mesepisternal tubercles absent. Dorsum of segments 8-9 black 
Bah cy che. Nba VIN Seely ele inline! Eoaonat es GHW Tred tibialis, p. 299 
275. Argia agrioides Calvert 
Calv. ’95, p. 476: Mtk. Cat. p. 45: Wmsn. ’14, p. 444: Smn. ’27, p. 12. 
Var: nahuana Calv. 
Length 28 (o’)-35( 2) mm. Expanse 37-45 mm. Calif., Ariz. and Tex. 
A southwestern Argia, that frequents desert streams. 
Male.—Head predominantly pale with black lattice-like streaks on the ver- 
tex. Dorsum of the middle and posterior lobes of the prothorax narrowly black, 
with a median geminate pale stripe of blue; anterior lobe and sides broadly pale, 
except for a fine sinuate lateral line of black. Meso- and metathorax predomi- 
nantly pale with the black middorsal stripe little or usually no wider than the 
pale antehumeral stripe. The humeral dark stripe is irregular, narrow and 
alberta 

forked, the posterior fourth appears as a basal spot, followed for another quarter 
of the length of the humeral suture by a fine brown line, the third quarter of the 
stripe is broad and subrectangular with a tail-like process trailing off posteriorly 
across the mesepimeron, giving the humeral a forked appearance, the fourth 
