133 

 Smith and Pritchard: Odonata 



Fig. 4:50. Hamules of Sympetrum. a, ambiguuw; b, costiferum; 

 c, danae, d, internum; e, madidum; f, obtrusum; g, pallipes; h, 



rubicundu/um (Needhom and Westfall, 1955). 



Females 



1. Genital plate entire or shallowly emarginate 2 



— Genital plate deeply emarginate and divided 4 



2. Tibiae entirely black 3 



— Tibiae pale, at least on outer face costiferum 



3. Genital plate broadly angulate mediodistally danae 



— Genital plate broadly emarginate mediodistally 



occidentale calif ornicum and atripes 



4. Tibiae entirely black 5 



— Tibiae pale pallipes 



5. Radial planate subtending 1 cell row 6 



— Radial planate subtending 2 cell rows madidum 



6. Vulvar lamina with lobes widely divaricate 7 



— Vulvar lamina with lobes contiguous obtrusum 



7. Vulvar lamina inflated with lobes directed dorsad 



rubicundulum 



— Vulvar lamina not inflated, with lobes not directed 

 dorsad internum 



Naiads 6 



1. Dorsal hooks on segments 6-8 as long as the segments 

 which bear them; lateral appendages half as long as 

 the inferiors, the latter not acuminate; lateral setae 9; 

 mental setae 12 occidentale calif ornicum 



— Dorsal hooks shorter than the segments which bear 

 them; lateral appendages not as above 2 



2. Lateral spine of segment 9 equal to one-half lateral 

 margin of segment 9 including spine; lateral setae 12; 

 mental setae 12 madidum 



— Lateral spine of segment 9 not more than one-third 

 lateral margin of segment 9 including spine; lateral 

 setae usually less than 12, typically 10-11; mental 

 setae usually more than 12 3 



3. Lateral spines of segment 9 one-third lateral margin 

 of segment 9 including spine; dorsal hooks present on 

 segments 4 to 8, well developed; mental setae 13-14 



4 



— Lateral spines of segment 9 not more than one-fourth 

 lateral margin of segment 9 including spine; dorsal 

 hooks usually absent from segments 4 or 8 5 



4. Base of mentum of labium distinctly broader than 

 middle coxae and somewhat more than one-fourth the 

 greatest width; inhabitant of shallow marshy bogs and 

 lagoons costiferum 



— Base of mentum scarcely, if at all, broader than middle 

 coxae and about one-fourth greatest width; in small, 

 semipermanent ponds pallipes 



5. Dorsal hook present, though small, on abdominal seg- 

 ment 8 6 



— Dorsal hooks absent on segments 4 and 8 



obtrusum and rubicundulum 



6. Lateral spine of abdominal segment 9 about one-sixth 

 lateral margin; lateral setae 10-11 internum 



6 The naiad of atripes has not been described. 





Fig. 4:51. Wings of Tarnetrum corruptum 

 (Needham and Westfall, 1955). 



Lateral spine of abdominal segment 9 about one-fourth 

 lateral margin; lateral setae 1 1-12 danae 



Genus Erythrodiplax Brauer, 1868 



This is a largo genus of Neotropical dragonflies 

 which enters the southern margin of the United States 

 (Boror, 1942) (fig. 4:47). Only one species, Erythrodi- 

 plax funerea (Hagen) 1861, has been recorded from 

 southern California. It is a wide-ranging form occurring 

 from California and Texas south to Ecuador. The 

 naiads live in tangled submerged vegetation. 



Genus Orthemis Hagen, 1861 



A Neotropical genus with one brown and red species, 

 Orthemis ferruginea (Fabricius) 1775, reaching the 

 southern border of the United States from California 

 and Utah to Florida (fig. 4:43). The nymph is elongate, 

 with a subcylindric and slowly tapering abdomen. 



Genus Belonia Kirby, 1889 



This is a western group of dragonflies with dark red 

 or reddish wings closely related to Libellula. A big 

 red species, Belonia saturata (Uhler) 1857, is the 

 only one in our territory. This very common form 

 ranges throughout much of the territory west of the 



Fig. 4:52. Wings of Erythemis simplicicollis 

 (Needham and Westfall, 1955). 



