HENRY J. FRANKLIN. 249 



94. Apical abdominal segments bearing more or less light yellow or 



ferruginous-yellow pile ; malar space short, not one-fourth 



the length of the eye terricola. 



Apical abdominal segments bearing little or no light pile ; malar 

 space at least one-fourth the length of the eye 95. 



95. Scutellum covered with dense yellow pile. Southwestern. 



sonorus. 



Scutellum usually dark, with only a very slight touch of yellow 



pile. Cosmopolitan penusylvanicus. 



96. Malar space fully one-third the length of the eye 84. 



Malar space less than one-third the length of the eye ; fourth ab- 

 dominal segment covered above with black pile. 



occidentalis nigroscutatus. 



97. Third abdominal segment covered with black pile above. 



frigidus. 

 Third abdominal segment covered with ferruginous-red pile above. 



centralis. 



98. Apical abdominal segments bearing ferruginous pile above. 



frigidus. 

 Apical abdominal segments bearing light or yellow pile above. 



couperi. 



99. Greater part of dorsum of thorax strongly shaded by the mixing 



of yellow and black hairs bolsteri. 



Black interalar band fairly well defined, black and yellow hairs 

 not mixed to any extent on the dorsum of the thorax. 



couperi. 



Table for Separation of Workers of Bombus. 



1. Face with a considerable amount of light or yellow pile 2. 



Face with very little or no yellow pile 29. 



2. Pleura, or at least their lower parts, covered with black pile or 



so shaded by the admixture of dark hairs as to be noticeably 

 darker than the front part of the thorax above ; yellow pile 



not reaching bases of legs..... 3. 



Pleura covered with yellow pile to bases of legs 11. 



3. Scutellum with very little or no light or yellow pile 5. 



Scutellum with considerable light or yellow pile 4. 



4. Abdomen with more or less ferruginous-red pile on some of the 



dorsal abdominal segments 6. 



Abdomen with no ferruginous pile above 8. 



5. Apical abdominal segments with white pile occideutalis. 



Apical abdominal segments without white pile vosnesenskii. 



6. Pile very long and loose sylvicola. 



Pile not very long and loose 7. 



TRANS. AM. ENT. SOC, XXXVIII. (32) 



