1897.] Flora and Fauna of Mammoth Cave, Ky. 387 
=rufipes Meig.] only in lacking the white sutures on the abdo- 
men. The male hasa nearly conical, long haired body. One 
line.” 
Mr. Coquillett has prepared the following description from 
my specimens: 
“ Phora rufipes Meigen. Male and female. Brownish-black, 
palpi, halteres and legs yellowish. The four lowest median 
frontal setæ directed downward. Legs destitute of bristles ex- 
cept a pair at tip of inner side of each middle tibia and a single 
bristle at tip of inner side of each hind tibia. Abdomen of the 
male covered with rather long and nearly erect bristles. Wings 
hyaline, costa from base to tip of second heavy vein fringed 
with rather long bristles, second heavy veins forked at the 
apex, first slender vein arcuate at the base, then nearly straight 
to the tip. Length 2mm. to 3 mm.” (Coquillett.) 
This species appears to be less abundant than either of the 
other dipterous forms. It occurs in Mammoth Dome and in 
the Labyrinth, in association with the Sciara inconstans. It 
flies about more freely, and when disturbed does not again 
light near by. In the Mammoth Dome I found the species 
running about among the masses of Rhizomorpha, which are so 
abundant on very old and decayed timbers in that portion of 
the cave. 
MOLLUSCA. 
Carychium stygium. Nov. sp. (Plate X, Figs. 6-7.) 
Shell minute, white, pellucid, shining; whorls 5 to 5.5 in 
number, convex above and rather flattened below, apical whorl 
blunt-rounded in most specimens, occasionally more acute ; 
Suture deeply impressed, quite regular; aperture a little less 
than one-fourth total length of the shell, rather sharply angu- 
lar above and broadly rounded below, with its plane forming 
a very acute angle with axis of the shell ; lip reflexed in mature 
Specimens; many examples, but not all, with a sharp, white, 
and long denticle on the parietal wall near the junction of the 
upper portion of the apertural boundary ; the spire is generally 
quite regularly and narrowly conical, but the body whorl is 
