392 Stainforth: The Guests of Yorkshire Ants. 
Monotoma conicollis Aub., Scarborough, York. 
M. formicetorum Th., Scarborough, York.* 
Seven of these occur exclusively with the Wood Ant, 
Formica rufa. As 1 have yet to see the first nest of this 
species in the East Riding, my search in this particular area 
has not yet been very successful. I was delighted, however, 
on visiting Weedley with Mr. E. Bilton, on September 5th, to 
discover a specimen of the interesting Pselaphid, Trichonyx 
médrkelt. This occurred in a nest of D. flava. Besides being 
the first record for the East Riding, it is the second for the 
whole county. It has been previously found at Scarborough, 
about fifty years ago. 
Of the remaining British beetles of this class, several have 
a distribution south and north of the county, and therefore 
should occur in Yorkshire. For example, Oxypoda vittata 
has been found with D. fuliginosa in the south, the midlands, 
Scotland and Ireland. The five species immediately following 
occur with F. rufa. Of these, Oxypoda recondita occurs in 
the south, Leicestershire, and Scotland; Scydmaenus godarti 
as far north as Sherwood Forest and Manchester ; Ptenidium 
myrmecophilum in the Northumberland district as well as in 
the south; P. kraatzi as far north as Leicestershire, and is 
also said to occur at Rannoch; and Dendrophilus pygmacus 
in the south, Northumberland district and Scotland. 
Six or seven beetles of this class are of a strictly southern 
distribution. In a thickly populated, highly cultivated and 
industrial area as England, it is only remotely possible that 
these will ever spread as far north as Yorkshire, but will 
persist as more or less isolated colonies. 
Among the ‘ indifferently tolerated lodgers’ are included a 
few spiders. The best known type is Thyreosthenius biovatus 
Camb., which lives in the nests of Formica rufa. Mr. W. 
Falconer has taken it at Danby Dale, near Huddersfield, and 
it will probably be found wherever the host ant occurs. It isa 
* It will be noticed that many of these records are for the Scarborough 
district. They are based on a brief note by T. Wilkinson, of Scarborough, 
which appeared in the Entomologist’s Monthly Magazine for June, 1865, 
page 14. As this early number is not so easily accessible, it may be worth 
white reprinting the paragraph referred to, which is as follows :— 
‘Ants’ NEsT BEETLES AT SCARBOROUGH.—On the 28th April, I 
made my first essay at examining some nests of Formica rufa, which 
are plentiful in woods near this place, and soon found several specimens 
of their beetle tenants, some of which were in abundance. I send a 
list of their names, thinking it may be of interest to some ‘of the readers 
of The Entomologist’s Monthly Magazine, as showing the northern 
prevalence of our southern forms. Thiasophila-angulata, Dinarda 
Markell, Oxypoda formiceticola, Oxypoda haemorrhoa, Homalota 
flavipes, Homalota anceps, Homalota parvallela, Leptacinus formicetorum, 
Monotoma angusticollis. 1 also met with other species which are not 
peculiarly ants’ nest beetles.’ 
Naturalist, 
