and Ancestral Form of Myrmecopliilous Coleoptera. 401 



Lasius fuliginosus at Oxshott in February, March, and 

 April. Harwood recorded it with the same ant at Col- 

 chester (E. M. M., 1899, p. 72). " In the company of ants, 

 Bishops Wood, Truro" (Vic. Hist. CornAvall, 1906, p. 190). 



Joy {I. c. p. 241) — " This is the characteristic beetle of 

 the owls' nest, where it may be found at any time of the 

 year, and I have twice taken single specimens in starlings' 

 nests. Although it has been before taken in owls' nests, 

 it is better known as the occasional inhabitant of the nest 

 of Lasius fuliginosiis. Microglossa ]julla has also the 

 double habitat; in the case of the latter there can be 

 little doubt that the chief host is a bird, and I think it is 

 also with M. gentilis. However, it is a curious fact that 

 M. gentilis has the habit, like a Myrmedonia, of curling itself 

 into the shape of an S and lying ' 'possum ' for a long 

 time, and it is fairly commonly found in the ants' nest. 

 M. pnlla has also this habit, but it is not so pronounced, 

 and it is a more irregular visitor to the ants' nests." 

 He then proceeds to point out that 31. nidicola, the sand- 

 martins' nest species, and which has not been found with 

 ants either here or abroad, has not the habit of curling up, 

 but always runs away when disturbed ; these facts also 

 bear out my own experience. 



Father Wasmann gives Lasius fuliginosus as the normal 

 host of this species, and as the regular guest of this ant in 

 Dutch Limburg, Avhere he took it in March, April, May, 

 June, July, September, October and November. It thus 

 appears that it cannot be the same specimens of these two 

 beetles which are found in the birds' nests and the ants' 

 nests, as we see that they are found at the same time in 

 both, and are therefore not double hosted in the sense 

 that they pass one part of their life with the one and the 

 rest with the other. It looks as if at some distant period 

 two sets of their ancestors had branched off into different 

 modes of life ; it might be that a bird's nest was in the tree 

 inhabited by ants, and the beetles found it a congenial 

 atmosphere, and then inherited the habit to seek birds' 

 nests, others remaining myrraecophilous. 



Again, the more pronounced myrmedonia habit of the 

 more regular inhabitant of ants' nests is very suggestive. 

 M. pidla, however, may have chosen birds' nests at an 

 earlier period, and may be losing the habit as it becomes 

 more fixed as a birds'-nests species. On the other hand, 

 as other species in the genus Microglossa are found almost 



