142 ENTOMOLOGICAL SOCIETY 



Antennae entirely black ; wings with apical margins white; subgenital 

 plate clothed with long hair. Length 27-37 mm. 



OBLiqUERUGOSA LllC. 



3. Fourth ventral segment with a lateral bunch of long curved hair; 



wings purplish ..ELEGANS. 



Fourth and fifth ventral segments with short hair; wings bluish, 

 shading into green and coppery apically CHARON Mocs. 



4. Apical margin or margins of wings pale or subhyaline 5 



Apical margins not pale or subhyaline 8 



5. Only the tips of anterior wings subhyaline; broadly fuscous at base 



and apically 6 



Tips of all wings subhyaline 7 



6. Subgenital plate crossed by a strong elevation at about middle, 



turned or bent downward at apex, so that viewed from the -side it 

 appears to be crossed by two strong carin3e....SANGUiGUTTA Christ. 

 Subgenital plate without median elevation, but bent downward at 

 apex; sixth ventral segment covered by a large chitinous plate, 

 the postero-lateral angles of which are drawn out into a narrow 

 process which completely encircles the sixth dorsal segment. 



CIRCULARIS FOX. 



7. Subgenital plate elongate, strongly punctured, clothed with long 



hair FORMOSA Say. 



Subgenital plate medially with a strong production which extends 

 laterally in the shape of a carina, apex reflexed or bent downward, so 

 that the plate, when viewed from the side, appears to be crossed by 

 two carinae; it is neither hirsute nor punctured CHRYSOTHEMIS. 



8. Subgenital plate crossed by a sharp elevation at about middle, turned 



or bent downward at apex, so that viewed from the side it appears 

 to be crossed by two strong carinae (extent of black and yellow of 



wings variable) CHRYSOTHEMIS Luc. 



Subgenital plate without median elevation, but crossed by a carina, 

 the apex at each side strongly produced ; sixth ventral segment cov 

 ered by a large chitinous plate the postero-lateral angles of which 

 are drawn out into a narrow fold, which completely encircles the 

 sixth dorsal segment CIRCULARIS Fox. 



9. Antennae from second joint orange (base and apical margin of wings 



distinctly darkened) MILDEI Stal. 



Antennae entirely black, or the pale color restricted to the apical 

 joints 10 



10. Subgenital plate short, spatulate, toward the base medially carinated; 



the hind margin rounded, fringed with hair; fourth ventral seg 

 ment with two bunches of curved hair, the fifth nude; antennae en 

 tirely black CERBERUS Luc. 



Subgenital plate elongate, sides parallel, not carinated, apex sub- 

 truncate, without hair; fourth segment with two bunches of curved 

 hair; the fifth with a transverse brush of shorter, stiff hairs; last 

 joint of antennae at extreme tip orange BOGUEI Fox. 



