[129] HYMENOPTERA 135 



ments i and 2 clothed with a yellowish pubescence, that on the two 

 basal segments is very sparse or interrupted medially ; the last three 

 abdominal segments with very sparse, pale yellowish hairs; thorax 

 above medially and on the scutellum with a grayish pubescence, the 

 anterior part of the thorax with yellow hairs well intermixed with 

 black, very much as in B. melanopygus Nylander ; dorsal abdominal 

 segments 3 and 4 with a black pubescence but usually (though not 

 invariably) interrupted by a narrow fringe of yellowish hairs extend- 

 ing from the apex of the second ; ventral segments fringed with a 

 sparse pale pubescence ; face with a yellowish pubescence more or 

 less mixed with black hairs ; legs with a long yellowish hair fringe, 

 that on the femora beneath is usually mixed more or less, with black 

 hairs. Malar space a little longer than wide. First joint of flagellum 

 a little longer than the third, the second hardly longer than thick and 

 only about two-thirds the length of the third. 



Worker. Length (major) 12 mm. ; (minor) 75 t 10 mm. 

 Both colored as in female, except that the pubescence on the face in 

 the worker minor is black or with only a few whitish hairs intermixed 

 with the black. 



Male. Unknown . 



Type. Cat. No. 5721, U. S. Nat. Museum. From Popof Island, 

 June 21 ; Yakutat, June 21 ; Virgin Bay, June 21 ; Fox Point, July 

 20. 



BOMBUS DIMIDIATUS sp. nov. 



Female. Length 12 mm. Mesopleura, the anterior part of the 

 thorax above, the apex of scutellum and the dorsal abdominal seg- 

 ments i and 2 clothed with a pale yellowish pubescence that on the 

 pleura is nearly white, on the anterior part of the thorax and the 

 scutellum mixed with black hairs on dorsal segments i and 2 inter- 

 rupted by a bare space medially ; otherwise, except some pale hairs on 

 the middle of the face and the apical fringe on the ventral segments, 

 the pubescence is black. Wings fuscous. Malar space about one- 

 third the length of the eye. First joint of flagellum nearly as long as 

 2 and 3 united, the second shorter than the third, not longer than wide. 

 Occasionally the black hairs on the apex of the third and fourth dorsal 

 segments of abdomen are well mixed with fulvo-rufous hairs, having 

 the appearance of two red lines across the black pubescence. 



Worker. Length 9 mm. Agrees in color with the female (or? 

 worker major) , except that the face is usually black or with only a 

 small tuft of pale hairs between and extending below the insertion of 

 the antennae. 



