244 AMERICAN HYMENOPTERA. 



28. Usually large queens with very dark wings 29. 



Medium sized or small queens with comparatively light colored 



wings rufocinctus. 



29. Dorsum of thorax wholly and densely covered with bright yellow 



pile morrisoni. 



A small rounded spot in middle of dorsum of thorax dark and 

 more or less bare nevadensis. 



30. Apical segments of abdomen bearing white pile alboanalis. 



Apical segments of abdomen not bearing white pile 31. 



31. First abdominal segment covered above entirely or for the most 



part with black pile ...32. 



First abdominal segment for the most part covered above with 

 light or yellow pile 35. 



32. Usually large queens with very dark wings 33. 



Medium sized or small queens with comparatively light colored 



wings rufocinctus. 



33. Ocelli large, placed well below the supra-orbital line in the narrow- 



est part of the front 34. 



Ocelli small, placed near the supra-orbital line occidentalis. 



34. Scutellum with at least a slight mixing of yellow hairs with the 



black ; apical segments of the abdomen without any ferru- 

 ginous pile auricomus. 



Scutellum always entirely black ; apical abdominal segments usu- 

 ally bearing more or less dark ferruginous pile....crotcliii. 



35. Malar space longer than it is wide at the apex ; pile long and loose..36. 

 Malar space not longer than it is wide at the apex ; pile short and 



dense rufocinctus. 



36. Some of the dorsal abdominal segments bearing a considerable 



amount of ferruginous-red pile ; hypopygium without a me- 

 dian carina gelidus. 



None of the abdominal segments bearing ferruginous pile above ; 

 hypopygium with a median carina pleuralis. 



37. Hairs fringing corbiculs with a more or less distinctly ferrugin- 



ous tinge 38. 



Hairs fringing corbiculae black 49. 



38. Yellow pile of pleura extending to bases of legs 39. 



Yellow pile of pleura not extending to bases of legs...edwardsii. 



.39. Face with little or no yellow pile about the bases of the antennae..40. 



Face with a large amount of yellow pile about the bases of the 



antennae 41. 



40. Malar space distinctly more than one-third the length of the eye. 



kirbyellus. 

 Malar space not one-third the length of the eye frigidus. 



41. Hypopygium with median carina on apical portion 42. 



Hypopygium without median carina , 46. 



