Parasitic Beetles. 419 



cinus formicetorum and Xantholinus ocliraceus (which, though 

 found in the nests, is probably not truly attached to the ants) . 

 Of the Histeridos, Saprinus piceus and Dendrophilus pygmceus 

 (and perhaps D. punctatus) ; and, of the Golydiadce, Monotonia 

 conicicollis and M. angusticollis frequeut these nests, where also 

 the larva? of the common rose- chafer, Getonia awrata, occa- 

 sionally live, and those of Glythra 4-punctata seem to have 

 their natural habitat, though the perfect insects of both these 

 species would never be suspected of such an origin. Another 

 unsuspected visitor is the rare and delicate Prionocyplion serri- 

 cornis, which has, on more than one occasion, been taken in 

 these nests. 



In the nests of Formica congerens, a species closely allied to 

 F. rufa, and occurring in Perthshire, the larva of Cetonia cenea 

 has its dwelling ; the perfect beetle having been observed to 

 fly down and disappear, burrowing in the huge mounds of 

 nests until it reaches a place judged fit for the deposit of its 

 eggs. Here also is found the little Homalota parallela. 



With Formica fusca cohabit Atemeles paradoxus and A. 

 emarginatus, Dinar da dentata, and the quaint pigmy Hetcerius 

 sesguicornis, with uni-articulate club to its antenna?. The nests 

 of this ant are very unlike those of the preceding, being merely 

 cells connected by intricate passages and galleries, excavated 

 beneath the surface of light warm banks, and usually having 

 their entrance under a stone. The Hetcerius seems to be an' 

 object of great care to the ants. Near the nests of this species 

 (and also with F. rufa) the large and handsome Aleochara rufi- 

 cornis has been captured. Homceusa acuminata was, also, first 

 introduced as British on the authority of a specimen taken in a 

 nest of F. fusca ; but subsequent investigation has shown, that 

 its true haunts are the runs or beaten paths worn by the thin 

 lines of scouts ever on the tramp near nests of F. fuliginosa, a 

 large jet-black ant usually building in decaying trees, from and 

 to holes near the roots of which hundreds of its shining 

 workers may be seen constantly hurrying. 



With the latter Myrmedonia humeralis and Quedius orevis, 

 at times so abundantly associated with Formica rufa, are very 

 rarely found; but other Myrmedonice in plenty supply their 

 place, no less than five species of that genus (funesta, laticollis, 

 lug ens, cognata, and limb at a) evincing a partiality for the 

 chewed woody fibres ejected from their galleries by the ants, 

 and deposited near the mouths of the burrows in moist ferment- 

 ing heaps. The first of these beetles, M. funesta, is often 

 exceedingly abundant, running about rapidly amongst the 

 troops of its friends, from which, on account of its similar 

 stature, equally shining mail, and deep black colour, it is not 

 readily to be distinguished. All these Myrmedonice have a 



