534 Mr. G. A. K. Marsliall on 



box on puipose to include the large Xyhcipa bee which it 

 mimics so admirably; but though usually they are common 

 enough I have not seen a single example for the last three 

 weeks. Tlie fly completely deceived me when on the 

 wing, but I happened to notice it settle on the trunk of a 

 tree, and it struck me there was something curious about 

 the way it alighted for a Xylocopa. \t is the only 

 example I have seen. 



Salisburi/, Ai)ril, 25, 1890. — I have already got a couple 

 of the jLi/l)copas for you, and I have seeu another 

 specimen of the Laphrid tiiat mimics them, but unfortun- 

 ately failed to catch it. 



ft. Si/r])hid Fill Miinicking a M^asp (Represented on 

 Plate XXII I). 



HVMENOPTEKA. Dll'TER.!. 



Poli.stes niargiualis (fig. 40). Ceria gambiaua (tig. 41). 



This is an excellent and typical case of Batesian 

 mimicry. The wasp is a very common species, building 

 a small haufjiniJ nest on bushes or ijrass-stems. Like most 

 of its congeners it is a somewliat sluggish insect, and in- 

 stead of flying away when approacheil, adopts a bold and 

 defiant attitude, stinging sharply when disturbed. It 

 visits flowers freely, and may there be seen in company 

 with the Ceria, which resembles it so closely (especially 

 on the wing) that I have been deceived by it over and 

 over anain. 



y. JJcc-likc (T/Y>«y) (Represented on Plate XXIII). 



llYMENOrTEKA. DllTEItA. 



Apidai. Si/rphidw. Asilidm. 



Megachile apiforrais Eiiinenis, sp. nov. ? I.axcnecera mollis 



(fi,'. 37). (lig. 38). (tig. 39). 



The resemblance of the two flies to the Megachile 

 is veiy marked in the field, especially in the case of the 

 Laxenccera ; although the plate does not do justice to the 

 Uumcrus- I have on several occasions seen all three 

 species flying together in the vicinity of flowers. 



