BOMBUS. 133 



7. Bombus ardens. 



Male. Length 7 lines. — Black, with the tarsi ferruginous ; the pu- 

 bescence on the head, thorax, and three basal segments of the 

 abdomen yellow, that on the abdomen palest ; head not elongated ; 

 the mandibles fringed with fulvous pubescence, as are also the 

 tibiae and tarsi ; wings pale fulvo-hyaline, the nervures ferruginous ; 

 the four apical segments of the abdomen clothed with fulvous pu- 

 bescence. 



Hab. Japan. 



8. Bombus unifasciatus. 



Female. Length 11 lines. — Black; the head oblong; the insect 

 clothed with black pubescence ; the third segment of the abdomen 

 with a fascia of bright yellow pubescence ; the wings brown-black, 

 with a violet iridescence. 



Worker. Length 5-7 lines. — Exactly agrees with the female in 

 every particular except size. 



Male. Length 6-8 lines. — Differs only in the yellow fascia extend- 

 ing on to the fourth segment of the abdomen. 



Hob. Guatemala, at an elevation of 5000 feet; San Francisco, 

 4500 feet ; Irazu, 6000-7000 feet. 



Bombus flavifrons resembles this species, but has yellow pubes- 

 cence on the head and prothorax. 



9. Bombus excellens. 



Female. Length 11 lines. — Black; the head, thorax, legs, and the 

 basal segment of the abdomen with black pubescence. The head 

 elongate ; the vertex and clypeus shining, the latter finely punc- 

 tured. The basal joint of the tarsi with obscurely ferruginous 

 pubescence within ; wiugs brown, the nervures dark fusco-ferru- 

 ginous. The abdomen with bright fulvo- ferruginous pubescence 

 on the second to fifth segments, the sixth segment shining and with 

 a few scattered black hairs. 



Hab. Venezuela. 



10. Bombus opifex. 



Worker. Length 6-6^ lines. — Black ; the pubescence on the head 

 and legs black, a broad band of the same between the wings ; the 

 thorax anteriorly, posteriorly, and on the sides clothed with yellow 

 pubescence, as are also the first, second, and third segments of the 

 abdomen ; on the following segments it is bright fulvous or fulvo- 



