114 



Smith and Pritchard: Odonata 



have barely room enough for her wing expanse. She 

 usually faced the center of the stream while ovi- 

 positing, though once she faced upstream and once 

 toward the bank." 



The naiads are hairy and lie buried to their eyes 

 in the soft mud and sand of slowly moving woodland 

 streams. They do not burrow with their fore feet but 

 kick out the mud with their hind feet and movements 

 of the body. The naiads may be carried downstream 

 during the three or four years required to reach matu- 

 rity. It is for this reason, Kennedy observes, that 

 oviposition is farther upstream than where the exuviae 

 are found. 



Family GOMPHIDAE 



Adult gomphids are clear winged, with yellow and 

 brown or black bodies, and the caudal end of the 

 male abdomen is more or less enlarged. They spend 

 much of their time perched on the ground or low 

 objects, making short flights. 



The naiads are found buried shallowly in the sandy 

 or muddy beds of streams or ponds. They do not 

 usually climb stems of plants for transformation but 

 move to the adjacent shore or objects on the shore. 



Key to Nearctic Genera 

 Adults 



1. Fore wing with nodus located beyond middle (fig. 4:16); 

 basal subcostal cross vein usually present 2 



— Fore wing with nodus at middle (fig. 4:4); basal sub- 

 costal cross vein absent .' 5 



2. Anal loop well defined, with 2 or 3 cells 3 



— Anal loop indistinct - 4 



3. Anal loop with 3 or more cells; male with inferior 

 appendage well developed and deeply forked 



Gomphoides Selys 



— Anal loop with 2 cells; male with inferior appendage 

 very small or not evident Phyllocycla Calvert 



4. Supratriangle with cross veins; triangle 3-sided • • • 



Aphylla Selys 



— Supratriangle without cross veins; triangle 4-sided 

 (fig. 4: 16) Progomphus Selys 



5. Triangle with a cross vein; anal loop with 4 cells 



Hagenius Selys 



— Triangle without a cross vein; anal loop with 3 cells 

 or less, if present (figs. 4:18; 4:6) 6 



6. Anal loop distinct, with 2 or 3 cells (fig. 4:18) 



Ophiogomphus Selys 



— Anal loop indistinct or absent (figs. 4:4; 4:21) 7 



7. Hind femur with many short spines and a row of promi- 

 nent long spines Dromogomphus Selys 



— Hind femur with many short spines only (fig. 4:26i) 



8 



8. Hind wing with cells below subtriangle twice as long 

 as wide (fig. 4:21); thorax with middorsal stripe yellow 

 and contrasting Octogomphus Selys 



— Hind wing with cells below subtriangle little longer 

 than wide; thorax with middorsal stripe dark 9 



9. Stigma distinctly wider than subtended cells (fig. 4:22); 

 male with forks of inferior appendage contiguous .... 



Erpetogomphus Selys 



— Stigma approximately as wide as subtended cells (fig. 

 4:4) 10 



10. Arculus with upper section much shorter than lower 



section; stigma about twice as long as wide 



Lanthus Needham 



Arculus with upper section similar in. length to lowei! 

 section; stigma more than twice as long as wide (fig J 

 4:4) Gomphus Leacbl 



Naiads 



1. Tenth abdominal segment shorter than 8th and 9tb 

 abdominal segments combined 2j 



— Tenth abdominal segment from about one-third the 

 length of the abdomen to nearly as long as all the 

 other segments combined (fig. 4:12e) 10 



2. Mesocoxae closer together at base than procoxae or 

 metacoxae (fig. 4:12z); 4th antennal segment elon- 

 gate, about one-fourth as long as the hairy 3rd 

 antennal segment (fig. 4: lie); burrow rapidly in sands 

 of rivers and lake bottoms Progomphus Selys 



— Procoxae and mesocoxae approximately same distance 

 apart at their bases (fig. 4:12/); 4th antennal segment 

 never as above, usually a small rounded knob (fig. 

 4:llc,<f) 3 



3. Wing cases widely divergent 4 



— Wing cases parallel along mid-line 5 



4. Dorsal hooks present on abdominal segments 2 or 3 to 

 9, hooklike and curved on caudal segments; lateral 

 anal appendages about three-fourths or less as long as 

 inferiors Ophiogomphus Selys 



— Dorsal hooks present only on abdominal segments 2 to 

 4, at most a slight thickening on the middorsal line of 

 segments 8 and 9; lateral anal appendages about as 

 long as inferiors Erpetogomphus Selys 



5. Third antennal segment ovate, flat, nearly as wide as 

 long (fig. 4:ll<i); lateral anal appendage about half as 

 long as inferiors 6 



— Third antennal segment elongate or linear, usually 

 cylindrical (fig. 4: 1 lc) 8 



6. Abdomen subcircular, almost as wide as long; body 

 depressed; paired tubercles on top of head 



Hagenius Selya 



— Abdomen at least twice as long as wide; no tubercles 

 on head 7 



7. Abdominal segments 7 to 9 with short lateral spines 



Octogomphus Selys 



— Abdominal segments 8 and 9 with short lateral spines 



Lanthus Needham 



8. Abdominal segment 9 rounded dorsally and without a 

 sharp dorsal hook, or, if dorsal hook present on abdomi- 

 nal segment 9, then the segment longer than wide at its 

 base (fig. 4:27) Gomphus Leach 



— Abdominal segment 9 with an acute middorsal ridge 

 with a dorsal hook at its apex, this segment never as 

 long as wide at its base S 



9. Mentum with median lobe moderately produced in a low 

 rounded curved spinulose border; abdominal segment 1C 

 a little longer than 9 Gomphoides Selys 



— Mentum with straight front border; abdominal segment 

 10 shorter than 9 Dromogomphus Selys 



10. Abdomen with sharp lateral spines on segments 6 or 7 

 to 9; labium with inner margin of lateral lobe entirely 



smooth, 3 teeth before end hook of lateral lobe 



Phyllocycla Calvert 



— Abdomen without lateral spines; labium with innei 

 margin of lateral lobe armed with large sharp pointed 

 recurved teeth, 4 or 5 teeth before end hook of lateral 

 lobe Aphylla Selys 



Genus Progomphus Selys, 1854 



The genus Progomphus (considered by Muttkowski, 

 1910, to be Gomphoides) is primarily Neotropical ir 

 distribution. Two species are wide ranging in the 

 United States. One species, P. obscurus (Rambur' 

 1842, is a greenish, yellowish species striped witr 

 brown (fig. 4:16). It is common in the eastern Unitec 



