ERPETOGOMPHUS 79 
for the species, as well as the one for the genus. In both wings triangles 
are rather long and free from cross veins, and there is no development 
of the anal loop. The long bifurcated inferior abdominal appendage 
of the male is sharply upcurved in its apical half. The female lacks 
occiptal horns. 
The nymphs of this genus are so like those of Ophiogomphus that 
up to the present time (1928) no means has been found for disting- 
guishing them. One species has been reared H. designatus (Hagen, 
’85, p. 255), and another, referred by supposition EL. compositus, has 
been described (Cabot, ’72, p. 4). 
This is a North American genus, with several species in Mexico and 
Central America, (one doubtfully reported from Brazil), but with most 
of the species occurring within our range. The adults may be dis- 
tinguished as follows: 
KEY TO THE SPECIES 
Adults 
MP PHCe Striped WithiBleeke 29 sched. Manis cs lathes x ore Roe 2. 
Pace NOMA PeGanl ETOAC Kr arte rrere eerie i ote, a 
2 Thoracic stripe 1 widest in middle............ diadophis, p. 79 
Thoracic stripe 1 not widest in middle.......lampropeltis, p. 79 
So eibipe a iree GUOVE wet... oes cane eee designatus, p. 80 
Stripe 2 fused with crest above............... compositus, p. 80 
23. Erpetogomphus diadophis Calvert 
Calv. ’05, p. 167: Mtk. Cat. p. 87. 
Length 48 mm. Expanse 58 mm. Tex 
Head and thorax yellowish green. Face greenish yellow with cross stripes 
of brown. Vertex and occiput brown. Thoracic stripes of the first pair separate, 
not reaching collar, wider in the middle; stripe 2 broad, isolated above, tapering 
downward; 3 narrow complete, narrowly confluent with 1 on crest; 4 and 5 very 
narrow, complete, 4 subobsolete. Legs blackish except for base of femora. Wings 
hyaline, more or less yellowish at base, especially in front; costa lined with 
yellow; stigma brown with black bordering veins. Abdominal segment 1 yellow; 
2 with a middorsal full length narrow yellow line; 3 and 4 with abbreviated mid- 
dorsal line conjoined with a transverse yellow one, the latter repeated on 5, 6 
and 7, interrupted in middle on 7. Round lateral spots on 3 to 7. 8 to 10 obscure 
brownish, paler on sides. Appendages brown. Male unknown. 
24. Erpetogomphus lampropeltis Kennedy 
Kndy. ’18, p. 297. 
Length 45 mm. Expanse 56 mm. Calif. 
Face grayish, cross lined with brown. Vertex brown. Thorax brownish in 
front with stripes 1 and 2 separated by isolated pale lines that diverge forward; 
