16. BOMBUS. 213 



with a pale yellow pubescence. The thorax clothed with yellow 

 pubescence, and having a black band between the wings, which is 

 more or less distinct ; the pubescence on the thorax beneath hoary ; 

 it is also pale on the legs. Abdomen — the pubescence on the first 

 and second segments yellow, on the third and fourth more or less 

 black, and sometimes crossed by a narrow fringe of yellow pubes- 

 cence on the apical margin of the third segment ; the fifth and sixth 

 segments with white pubescence ; the pubescence beneath yellowish 

 white. 

 Yar. (3. The four basal segments with yellow pubescence, with faint 

 traces of dark bands. This is the Bombus ericetorum figured by 

 Curtis. 



The typical specimen, a male, in the Linnean Cabinet is very like 

 the variety (3. The typical specimen of Linne's Apis terrestris, pre- 

 served in the Linnean Cabinet, is the female of this species. In this 

 country Bombus lucorum usually appears at an earlier period in the 

 season, according to my observation, than Bombus virginalis. The 

 latter is a rather larger insect ; its male is readily distinguished from 

 that of B. lucorum by its always having the entire head clothed with 

 black pubescence ; its maxillary palpi are different, and the second 

 joint is longer in proportion to the first joint. The nests of both species 

 have been taken in autumn, when all the sexes of each species have 

 been obtained. In a nest of Bombus virginalis all the females had 

 the apex of the abdomen tawny ; but it is probable that when indir- 

 viduals have been long exposed to weather, the tawny apex may 

 become more or less bleached to white ; I have found specimens of 

 the female with the apex of the abdomen white. On a female of 

 Bombus lucorum being shown to the late Prof. Boheman, he named it 

 B. terrestris of Linnseus ; whilst he pronounced the bee with the 

 tawny apex of the abdomen to be a species unknown to him, and one 

 not found in Sweden. In the type- collection of Kirby there is a 

 female with a white anus, which, in his remarks on Bombus terrestris, 

 he states to have been found by Mr. Trimmer in a nest of the 

 bee with the tawny apex of the abdomen ; this specimen is, in 

 my opinion, an example of B. lucorum. It is not an unusual 

 occurrence to find individuals of one species in a nest of another ; 

 thus I have found B. sylvarum in a nest of B. muscorum ; such 

 occurrences can only be regarded as accidental. The yellow bands 

 in B. lucorum are of a lemon-coloured yellow, whilst those of 

 B. virginalis are deep orange-yellow. 



It should be mentioned that the male organs of B. lucorum and of 

 B. virginalis have been compared ; and although the differences are 

 only slight, yet they are constant, and in my opinion quite justify 

 their separation as distinct species. 



