390 Stainforth: The Guests of Yorkshire Ants. 
nest of this species at Kelsey Hill, in Holderness, which 
measured about three feet by two and half feet, and about a 
foot in depth through the tunnelled portion. I made as care- 
ful a calculation as the circumstances would permit and arrived 
at the result that there would be about 2,300 feet of tunnels in 
the nest. This particular example abounded in various 
subterranean animals, all of them resembling Platyarthrus 
in being of a pure white colour, and some like this animal 
also belonging to the group of ‘ indifferently tolerated tenants.’ 
Besides Platyarthrus, there was the active little blind ‘ spring- 
tail’ (Collembolan), Cyphoderus albinos Nic. (also called Beckia 
albinos by Lubbock in his ‘ Ants, Bees and Wasps’); the 
‘ bristletail’ (Thysanuran), Campodea staphylinus, and Scuti- 
gerella immaculata, one of the Symphyla. 
Exactly the same association occurred in the nests of D. 
flava at Weedley Springs, on the Wolds, with the addition, 
however, of a white ‘ springtail’ I have not yet been able to 
identify. I have carefully compared the Scutigerella from 
Weedley with the descriptions in Bagnall’s valuable “ Synopsis 
of the British Symphyla,’* and it is certainly immaculata. I 
am hoping that among material still to examine there may be 
other species. Almost the same association is to be found in 
Scandinavia, for Schott, writing of Cyphoderus albinos, says 
that he “has; iound ate echt ent ain pee Streifziigen in 
nordlichen Upland, dann immer unter Steinen zusammen mit 
Scolopendrella ammaculata, Campodea staphylinus und einer 
roten Ameisen-Art.’+ Platyarthrus is not mentioned. Whether 
the isopod occurs in Scandinavia or not I am unable to say. 
At any rate it is not represented there in Scharff’s map of the 
geographical distribution of P. hoffmannseggi, given in his 
‘European Animals’ (1905), although it is shown to occur in 
Denmark. 
Leaving aside Platyarthrus, of these subterranean animals 
Cyphoderus is the only true myrmecophile, inasmuch as it is 
consistently found only in association with ants. It probably 
occurs throughout the county. I have always found it when I 
have searched specially for it in the East Riding, usually with 
Domnisthorpea flava, as at Weedley, Kelsey Hill, and North Cave, 
but also with Leptothorax acervorum at Holme-on-Spalding- 
Moor, and with Formica fusca at South Cave. Bagnallf says it 
= Trans) Nat, Elist; soc, Ny D> and N&@a(Ness); vol. [Ves partitapps 
17-41. 
+ ‘Frequently on expeditions in northern Upland, and always under 
stones, together with Scolopendrella immaculata and S. staphyiuinus and a 
red ant species.’ © Zur Systematik der Collembola,’ Kongl. Sv. Vet. Akad. 
Handy; Bdi25; Wi; 1892) ING. tr p44. 
t ‘Short Notes on Some New and Rare British Collembola,’ Trans. 
Nat. Hust. Soc; N., D:s,"and NIC, (N:S.), vol wm, part'2, ro09, pp: 504): 
Naturalist, 
