50 U. S, NATIONAL MUSEUM BULLETIN 209 



vein reaching the wing margin; base of first discoidal cell without a 

 distinct irregularity in the membrane; nervulus beyond basal vein 

 by about 0.2 to 0.7 its length; nervellus ending at, beyond, or some- 

 times just before juncture of cubitella with discoidella; anal lobe about 

 0.75 as long as submediella (pi. 1, fig, 5); dorsal edge of hind tibia of 

 female with a distinct serration, of male usually with a weaker 

 serration, or sometimes smooth; brush on inner side of hind tibia 

 rather narrow, with a subapical constriction or interruption; under 

 side of hind tarsus of male with a close fringe of hairs extending from 

 its base to beyond the middle (This fringe is absent in all other 

 Nearctic Pepsinae except Cryptocheilus.) ; last tarsal segment with two 

 regular rows of bristles beneath; tooth on tarsal claws erect, acute. 



This genus is restricted to the Western Hemisphere. It is closely 

 related to Cryptocheilus. Three species groups, of which two are 

 Nearctic, are known to me. See the keys and descriptions for their 

 characters. 



Key to the Nearctic species of Priocnemioides 



1. Brush on inner side of hind tibia not interrupted, only narrowed subapically; 



nipples on posterior part of apical margin of fore coxa weak; second sternite 

 of female with a pair of large, weak, cushionlike swellings but without 



tubercles, magntjs group 2 



Brush on inner side of hind tibia interrupted subapically, or in some females 

 not quite interrupted but very strongly narrowed subapically; nipples on 

 posterior part of apical margin of fore coxa well developed; second sternite 

 of female with a pair of more or less distinct tubercles surmounting a pair 

 of more or less distinct swellings, pulvicornis group 7 



2. Flagellum orange; wings black 3. magnus (Cresson) 



Flagellum black; wings orange to black 3 



3. Propodeum and upper part of metapleuron without any wrinkles; hind tibia 



of male with a dorsal row of distinct oblique teeth; hind tibia of female 

 with the teeth in its dorsal row rather wide, about as wide as the length 



of the bristles beyond each tooth, subspecies of texanus 4 



Propodeum and upper part of metapleuron with at least a few transverse 

 wrinkles; hind tibia of male with a dorsal longitudinal ridge on which teeth 

 are faintly indicated; hind tibia of female with the teeth in its dorsal row 

 narrow, about 0.75 as wide as the bristle beyond each tooth 5 



4. Wings almost entirely blackish . . 4a. texanus atripennis, new subspecies 

 Wings mostly orange 4b. texanus texanus (Cresson) 



5. Temple receding behind the eye, so that the head is distinctly narrower across 



the temples than across the eyes; propodeum and upper part of meta- 

 pleuron usually completely covered with wrinkles; head and thorax with 

 a rather strong, usually greenish blue iridescence, especially in the female; 

 erect hairs on thorax very long and dense .... 1. aratus, new species 

 Temple not receding behind the eye, the head about as wide across the tem- 

 ples as across the eyes; propodeum and upper part of metapleuron usually 

 only partially covered with vsrinkles; head and thorax with a faint purple 

 iridescence; erect hairs on thorax shorter and sparser, subspecies of 

 AUSTRINUS 6 



