DASYGASTRES MASON-BEES 



35 



social ; but this is doubtful, Bates having recorded that £. sur- 

 inamcnsis forms a "solitary nest." Lucas concluded that £. 

 cordata is social, on the authority of a nest containing " a 

 dozen individuals." 'No workers 

 are known. The species of 

 Eidema have a shorter tongue 

 than Uuglossa, and in form 

 and colour a good deal re- 

 semble our species of Bombus 

 and ApatJnis. 



The group Dasygastres in- 

 cludes seven European genera, 

 four being British {Chelostoma 

 being included in Heriaclcs). 

 The ventral surface of the hind 

 body is densely set in the 

 females with regularly arranged 

 hairs, by means of which the 

 pollen is carried. In many of 

 the Dasygastres {Majavli He, 

 e.g.) the labruni is very large, 

 and in repose is inflected on 

 to the lower side of the head, 

 and closely applied to the 

 doubled -in tongue, which it 

 serves to protect ; the man- 

 dibles then lock together out- 

 side the labrum, which is thus completely concealed. This group 

 includes some of the most interesting of the solitary bees. 



The genus Chalicocloma is not found in our own country, but" 

 in the South of France there exist three or four species. Their 

 habits have given rise to much discussion, having been described 

 by various naturalists, among whom are included Eeaumur and 

 Fabre. These Insects are called mason-bees, and construct nests of 

 very solid masonry. 0. 7nuraria is in appearance somewhat inter- 

 mediate between a honey-bee and a Bombus ; it is densely hairy, 

 and the sexes are very different in colour. It is solitary in its 

 habits, and usually chooses a large stone as a solid basis for its 

 habitation. On this a cell is formed, the material used being 

 a kind of cement made by the Insect from the mixture of a 



Fig. 18. — Euglossa cordata, i. Amazons. 



A, The IiLsect with e.xtended proboscis ; 



B, outer face of hiud tibia and tarsus. 



