COLLEMBOLA— ENTOMOBRYID^. 55 



This species is probably confined to subterranean life. It is so 

 transparent that the rays of sunlight would certainly penetrate to its 

 internal organs. Garman (1839, 229) quotes Miss Hoppin regarding 

 the occurrence of this insect, doubtless, in a well in southwestern Mis- 

 souri, as follows: "The owner reports that at various times, a year or 

 more ago, the surface of the water would be covered with little white 

 lice or something of the kind." 



I found this species in Mayfield's, Truett's, Donaldson's, and Twin 

 caves in Indiana and Mammoth ,Cave, Kentucky. 



Carpenter (1895, 30) found another species of Sinella (Sinella cav- 

 erniola) in Michelstown Cave in Ireland, which species he says is very 

 hard to seperate from Sinella cavernarum Packard. In fact, he seems 

 to incline to the view that the two are really the same species. 



Tomocerus niger Bourlet. 



BOURLET, Mem. Soc. Roy., Lille, 1839. Lubbock, CoUembola and Thysanura, 

 London, 1873, 139-146. 



Fairly common under stones and sometimes on the wall or roof from 

 the mouth to "11" and once or twice was taken as far in as " 25. " It is 

 steel-gray in color. It seems perfectly at home in the cave. This 

 species is sensitive to light, which it avoids. Mr. J. W. Folsom says it 

 differs but slightly from European specimens. According to the same 

 authority specimens collected out of doors in the immediate neighbor- 

 hood of the cave are almost typical as compared with European specimens. 



Packard (1888, 66) found Tomocerus -plumbeus var. pallidus in the 

 Carter Caves in Kentucky and in Weyer's, New Market, and Fountain 

 Caves in Virginia, and reports another variety (albida) from a small 

 cave in Utah (see also 1877, 159) . This variety is bleached and many 

 of the individuals are almost white. Its eyes are small and dark colored. 

 Normal -pallidus was found in Hundred Dome Cave and in other ' 'shal- 

 low" caves in Kentucky. Packard (1888, 67) has also described another 

 member of this family from caves, Lepidocyrtus atropurpurevs from 

 Diamond Cave, Kentucky, and Smynthurus ferrugirteus from New 

 Market and Weyer's caves in Virginia. Neither of these is a true cave 

 form. 



Call (1897, 38) more recently found in Mammoth Cave Entomobra 

 cavicola Banks, a white eyeless species, and Smynthurus mammouthia 

 Banks, a white species with small eyes. 



There are many European species of this family found in caves; 

 among them being two eyeless species of Tritomurus, closely related to 

 Tomocerus, and Tomocerus nivevs Joseph (Hamann, 1896, 146) . 



Several other families of Aptera have cave representatives. 



