1 8 Myro)i Harmon Swcnk 



10. Larger species, 8-8.5 ""H- l'^"g ^ ^ 



10. Smaller species, 5-7 mm. long 12 



II. Pygidium covered with dense long appressed hair above; fringe 

 of white hair on apical margin of tergite 5 erect and very con- 

 spicuous ; propodeum black with a broad red band on each 

 side ; metanotum black ; mesoscutum and pleura red suffused 

 with dusky : apical margin of tergite i not distinctly blackish ; 



8.5 mm z'icinalis 



II. Pygidium above much less densely haired, the hairs short and 

 inconspicuous; fringe of white hair on apical margin of tergite 

 5 much shorter and less conspicuous ; propodeum red except 

 a small black spot at extreme apex of enclosure ; metanotum 

 largely red: apical margin of tergite i blackish; 8-8.5 mm. 



cressonii 



12. Abdomen immaculate red except for a small yellow spot on sides of 

 tergite 2; joint 3 of antennae three-fifths as long as 4; size 

 very small, 5 mm iiiiuuta 



12. Abdomen red but usually with distinct spots on sides of tergites 2 



and 3 ; size larger, 6-7 mm 13 



13. Joint of antennae about four-fifths as long as 4; lower corners 

 of face yellow or yellowish; pygidial area more rounded; a 

 transverse spot on tergite 5, which may be broken in two, in 

 addition to the lateral marks on tergites 2 and 3 and rarely 



on 4 also : 6-7 mm illiiioiensis 



13. Joint 3 of antennae only about three-fifths as long as 4; lower 

 corners of face red and but rarely even suffused with yellow- 

 ish : pygidial area somewhat truncated at apex; no yellow on 

 abdominal tergites 4 and 5 but usually with lateral marks on 2 

 and 3 14 



14. Propodeum red, the suture with the metapleura broadly black ; 6-7 

 mm sayi 



14. Propodeum black with the angles and the base of the enclosure red; 



7 inni propinqua 



(The females of pallidipicta. aprilina. bicrista, saiicicola and parallcla 



are unknown or unrecognized.) 



Males 



Joint 3 of antennae about one and one-third times as long as 4; sides of 

 propodeum covered with a peculiar appressed silvery sericeous 

 pubescence ; head and thorax black with the clypeus, mandible 

 bases, labrum and lateral face marks, yellow, an orbital ring, 

 the mesoscutellum, metanotum, most of mesopleura, usually large 

 areas on the sides of mesoscutum. and legs, red ; abdomen 

 wholly red ; 6-9 mm adducta 



IS 



