398 Mr. H. St. J. Donisthorpe on the Origin 



an indifferently treated lodger (Wasmann, Zeitscli, f., 

 wissenschaft, Insekten, 1905, Heft 8, p. 830, and Wheeler, 

 New York Ent. Soc, 1908, iii, p. 135, etc.). There is 

 also a wonderful beetle, Mi/rmechusa mirahilis, described 

 by Father Wasmann, which is intermediate between the 

 genera Lomcchusa (true guests), and Mijrmedmiia (hostile 

 persecuted lodgers). This looks as if a Ifyo^mcdonia-Wke 

 species had acquired some of the habits, hairiness, etc., of 

 a Lomcchusa. 



The following table may represent the evolution of the 

 myrmecophilous species, according to the facts and views 

 expressed in this paper. 



Non-Myrmecophilous Species. 

 Bird's-nest Species 



"■■Occasional visitors to ants. 

 More frequent visitors. 

 Ancestral forms (unknown). 

 Present Myrmecophilous species. 



Indifferent tolerated lodgers. 



Hostile persecuted lodgers. 



""■■-True guests.,-'' 



I will now deal with the species of Coleoptera which 

 are occasionally, or often found with ants, or in ants' 

 nests in Britain, but more generally away from them, and 

 give all the records and evidence, on such occurrences, of 

 which I am aware, of each of them. 



Aleochara o^njlcornis, L. 



This species is widely distributed in Britain, but always 

 rare. Janson (Ent. Ann., 1857, p. 93) writes — " I have 

 likewise taken, by brushing herbage in the neighbourhood 

 of the nests oi Formica fu sea, the rare Aleochara rnficm^nis, 

 and have little or no doubt it is a truly myrmecophilous 

 insect, although not hitherto recorded as such." Again 

 {I. c. 1858, p. 81) — " Dr. Power found, this spring, an in- 

 dividual of this scarce species, beneath dead leaves, in the 

 vicinity of a nest of Formica rufa, a few yards distant 



