26 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loo 



13 (9). Thorax yellowish in color 11 



Thorax not yellowish in color 16 



14 (13). First and second bands faintly joined at costal margin. 



R. muuda, new species 

 First and second bands widely separated at costal margin 15 



15 (14). Apical part of aedeagus little shorter than basal part; apical part with 



definite neck, not appressed to basal part. R. imitabilis, new species 



Apical part of aedeagus longer than basal part; apical part with no 



apparent neck, appressed to basal part R. pallida Loew 



16 (13). The part of first basal cell contiguous to second basal cell with hyaline 



area sharply wedgelike toward base of second basal cell. 



R. winifredae, new species 



That part of first basal cell with hyaline area not sharply wedgelike, 



either rounded toward base or completely hyaline 17 



17 (16). All femora yellowish 18 



At least middle and bind femora blackish 22 



18 (17). Second and third bands definitely converging tov/ard their tips; fourth 



band not conspicuously broadened at tip of third vein; the part of 

 first basal cell contiguous to second basal cell completely hyaline or at 



most very faintly banded at base R. cognata Cresson 



Not with above combination of characters 19 



19 (18). Pruinosity on posterior dorsal corner of mesopleuron in the form of a 



rectangle; the part of first basal cell contiguous to second basal cell 



at most faintly banded basally 20 



Pruinosity on posterior dorsal corner of mesopleuron in the form of a 

 right triangle; the part of first basal cell contiguous to second basal 

 cell usually darkly banded basally 21 



20 (19). Apical part of aedeagus with lateral finlike structure on each side; 



fourth band usually widely separated from third band at costal 



margin R. texana, new species 



Apical part of aedeagus with no lateral finlike structure; fourth band usu- 

 ally narrowly joined to third band at costal margin . R. vaga, new species 



21 (19). Width of fourth band at tip of third vein equal to or longer than length 



of posterior crossvein R. severini Blanton 



Width of fourth band shorter than length of posterior crossvein. 



R. micans Loew 



22 (17). Front legs with coxae, tibiae, and femora of uniform yellowish color; 



the part of first basal cell contiguous to second basal cell hyaline, at 



most faintly banded basally 23 



Front legs with coxae, tibiae, and femora blackish; the part of first 

 basal ceU contiguous to second basal cell darkly banded basally . . 24 



23 (22). Third antennal segment obtusely rounded at tip; width of fourth band 



at tip of third vein as long as length of posterior crossvein. 



R. michiganensis, new species 



Third antennal segment pointed at the anterior end of tip; width of 



fourth band at tip of third vein shorter than length of posterior 



crossvein R. flavimana Loew 



24 (22). Cerci of males extend beyond the proctiger by at least the length of 



the proctiger R. mclliginis (Fitch) 



Cerci of males do not extend beyond the proctiger or do so only slightly. 



R. viridulans Robineau Desvoidy 



25 (1). Thorax yellowish 26 



Thorax dark brown or blackish 27 



