Cases of Protective Resemblance, Mimicry, etc. 351 



STAPHYLINID/E. 



Atemelcs. 



Father Wasmann says of Lomechnm strumosa, which is 

 very like an Atemeles but larger (and the following remarks 

 will equally apply to our two species of Atemeles), that the 

 similarity between the beetle and the ant depends more 

 on deceptive reflexions of light, than upon real similarity 

 of form. He points out that the beetle lives in the midst 

 of the ants, and though away from them it does not in the 

 least suggest the appearance of an ant, when it sits in their 

 midst, the light reflected by the concave sides of the thorax 

 appears to the eye like the narrow back of the ant, while 

 the rolled-up abdomen of the beetle reflects the light in 

 the same way as the rounded abdomen of a large ant. 

 Consequently it is very difficult to detect them in their 

 normal environment. 



Myrmedonia collaris, Payk. 



When I took this beetle in numbers, with its host 

 Myrmica Itevinodis, in Wicken Fen, I also took with it 

 several specimens of an ichneumon, Microcryptus nigro- 

 cinctus, Grav. ($s). Both beetle and ichneumon are 

 coloured in the same way, being banded alternately black 

 and red, and much resembled each other when running 

 on the paper. Mr. Morley tells me " the coloration is 

 decidedly unusual in an ichneumonid." On the other 

 hand, the colour of the beetle is also entirely different 

 from that of the rest of our species. This may be a 

 case of true mimicry of the beetle for the ichneumon, 

 but the fact that they both have a superficial resemblance 

 to the ants might indirectly account for their mutual 

 similarity. 



Myrmedonia fiinesta, Grav. 



This beetle, which is found in and about the nests of 

 the jet ant, Lasius fnliginosus, is very like its host in 

 appearance ; the resemblance being caused, as pointed out 

 by Father Wasmann, by its glossy black colour, narrow 

 shape, and rolled-up abdomen. When disturbed its second 

 line of defence consists (in common with all the other 

 species of Myrmedonia and indeed with very many other 

 species of Coleoptera) in curling itself up ; when remaining 



