THE FAUNA OF A COAL-PIT AT GREAT DEPTHS 185 



9. Phora (Apkiocheetd) rufipes, Mg. This well-known, easily 

 recognised, and very common species was reported to be of 

 frequent occurrence in the mine. I find that, under normal 

 conditions, it has been bred from Lepidoptera, decaying caterpillars, 

 beetles, rotten potatoes, and fungi. A single specimen was 

 submitted for examination. 



COLLEMBOLA. 



10. The most common of the insects captured were small, 

 almost black, Springtails, whose leaping habit is well characterised 

 by the miner's name of "pit-fleas." The "pit-fleas,' : all the 

 specimens of which examined belonged to the species Tomocerus 

 minor (Lubbock), were common and widely distributed, not only 

 in the incline, but in other parts of the pit. They were found 

 on the coal, the rock, and the pit-props, in both wet and dry 

 places. It is scarcely surprising that a creature which is, according 

 to Mr Wm. Evans, "very generally distributed, and by far the 

 commonest species of the genus here [in the Edinburgh district] 

 . . . found under stones, logs," 1 etc., should occur in a Midlothian 

 coal-pit. It has almost certainly been introduced with the fir logs, 

 and a predisposition to a life in obscurity would render easy its 

 establishment in the total darkness of the mine. Indeed, the 

 species has been recorded from the Irish caves of Mitchelstown 

 and Coolarkin from the former by Wright and Haliday, and 

 more recently by Jameson, from the latter by Jameson ; and from 

 North American caves by Packard. 2 



The species is variously known as Tomocerus minor, T. 

 tridentiferus, or, as in Lubbock's Ray Society Monograph, T. 

 plumbeus. From the recent description of the species given by 

 Linnaniemi (Axelson), 3 the Niddrie specimens differ in having 

 the five to seven small teeth on the inner surface of the large 

 claws practically obsolete, and in having rarely nine, instead of 

 a minimum of ten, dental spines. In this latter point, however, 

 they agree with Lubbock's description of T. plumbeus. 41 



1 Carpenter and Evans, " Collembola and Thysanura of the Edinburgh Dis- 

 trict," Proe. Roy. Physical Soc, vol. xiv., p. 237, as T. tridentiferus. 



2 Jameson, "Caves of Enniskillen and Mitchelstown," in Irish Naturalist, 

 vol. v., 1896, as T. tridentiferus. 



"' Linnaniemi, "Die Apterygotenfauna Finlands, II., Spezieller Teil," in Acta. 

 Soc. Scient. Fennicas, torn, xl., No. 5, 191 2, p. 181. 



4 Lubbock, " Monograph of the Collembola and Thysanura," Pay Society, 

 1873, p- 139- 



32 2 A 



