1897.] Flora and Fauna of Mammoth Cave, Ky. 381 
densest darkness, the security of the under surface of their 
shelters. It would seem.that this habit, which is quite general 
for all the cave species observed by me, would be a strong argu- 
ment in direct proof of the outside origin of the fauna as a 
whole. While many generations have passed these forms hide 
in the regions of perpetual darkness as completely and system- 
atically as do their cousins and nearer relatives of the surface. 
It is further interesting to note that this species is eyeless, a 
fact to which Mr. Banks calls attention in his description. 
“Smynthurus mammouthia Banks. Nov. sp. (Plate X, Fig. 1.) 
“Length 1mm. White hyaline. Eyes distinct; antenne 
have the first joint very short; second twice as long; third 
equal to second; fourth much longer, divided into five parts, 
the basal one long, the following three short, subequal, and a 
longer, slender one at tip; all, except the last joint, with hairs 
at tip. Legs are moderately long, two claws at the tip, each 
with a tooth above, the outer claw as long as the width of the 
tibia. There is a small tooth below on the dentes before the 
tip, and a larger one on the outside at tip over the insertion of 
the mucrones; the latter are shorter than the dentes, finely 
serrate below and with curved tip. Quite a number of short 
hairs on the posterior half of the abdomen, and on the anal 
tubercle. Three specimens, Mammoth Cave, Kentucky.” 
(Banks.) 
Of these specimens one was found in association with the 
form described above, while two were found under damp stones 
near Richardson’s Spring, in the Labyrinth. The form moves 
slowly about, under the influence of the heat from the lamps, 
but springs very like the Entomobrya when the attempt is made 
to take it. The white color alone enables one to detect it 
during its slow crawling movements; a considerable number 
escaped before they could be seized, dirt and all, by the forceps. 
I judge the species to be fairly common, since one of my note- 
books records the form as oceurring in some numbers as fol- 
lows: “Small mite-like forms abundant under sticks near 
Richardson’s Spring; with them are rare examples of Anthrobia 
mammouthia Telkpf.” Mr. Banks’ figures are very character- 
