HENRY J. FRANKLIN. 183 



bles of the females (I have examined those of a worker deter- 

 mined by Schmiedeknecht and found them to be as described 

 and figured by him in Apid. Europ., I, P. 5, 1883, p. 373; 

 T. 12, Fig. 2) are distinctly six-toothed. I know of no other 

 species of Bombjcs normally with more than four distinct 

 teeth to the mandible, and Schmiedeknecht (vide supra) 

 states that niastrzicahis may be readily distinguished from all 

 other species of bumble-bees by means of the toothed man- 

 dibles of its females. Is not this remarkably specialized 

 structure of the mandibles due to some peculiar specializa- 

 tion on the part of this species in its habits of nest building? 

 The genitalia of the male of alpigenus Morawitz, as figured 

 by Radoszkowski under the name ivurfleini (Bull. Soc. 

 Natural. Moscou, LIX, 1884, p. 65; T. 1, Fig. 9), would 

 place that species in this group, but I know nothing of its 

 other characters. Schmiedeknecht (Apid. Europ., I, P. 5, 

 1883, p. 373) placed alpigemis as a variety of mastrucatus. 



3. Other Groups. 



B. vorticosjis Gerstaecker (as described and figured by Sch- 

 miedeknecht in Apid. Europ., I, P. 5, 1883, p. 319, n. 11, 

 9 $ cf; T, 8, Fig. 7), mendax Gerstaecker (as described 

 and figured by Schmiedeknecht in the same work), and con- 

 fusus Schenck all belong to the subgenus Bo7)ibias. I have 

 seen a worker of mendax, determined by Schmiedeknecht. 

 Its ocelli were placed distinctly below the supra-orbital line, 

 but slightly above the narrowest part of the vertex, the 

 lateral ones being nearer to the margins of the eyes than to 

 each other. I have seen specimens (determined by Schmie- 

 deknecht) of all three castes of conhcsus and have examined 

 the genitalia of the male. Many of the characters of this 

 species, if other characters were not considered, would place 

 it readily in the Fraternus group. The ocelli of the females 

 are large and placed in the narrowest part of the vertex, well 

 below the supra-orbital line, the lateral ones being nearer to 

 the margins of the eyes than to each other ; the eyes of the 

 male are greatly swollen and the ocelli are placed in the 

 narrowest part of the vertex, at about one-third of the dis- 



TRANS. AM. KNT. SOC, XXXIX. 



