744 THE MAMMOTH CAVE AND ITS INHABITANTS. 
like fibres are often produced. - Very commonly, however, the 
erystals begin to form when a small nodule of the iron ore is ex- 
posed at the surface; the parts first formed become attached to 
the surface around the edges, and as the chemical action proceeds 
towards the centre of the nodules successive leaf-like layers are. 
thrown out, and the rosette form is the result. Along lines of 
fracture in the surface of the rock, the crystals are curved in op- 
posite directions. 
The wreaths and other figures formed by the chains of the ro- 
settes, may be caused by the chemical action described taking 
place around the edges of large masses or concretions of the iron 
or 
e. 
These crystalline forms occur only in the dryer parts of the 
cave. Where there is more moisture, as in the ‘ Snow-ball room, 
the gypsum merely forms white, rounded concretions, originating 
from nodules of the iron ore on the roof and sides of the cave.” 
With these general remarks on the cave we give a brief account 
of its interesting fauna, comprising representatives of the Fishes, 
Insects, and Crustaceans. No Mollusks or Radiates have as yet 
been discovered, but the lower forms of life have been detected 
by Tellkampf, who collected several species belonging to the gen- 
era Monas, Chilomonas, and (2) Chilodon. 
On tHE BLIND FISHES or THE Cave. By F. W. Pornam. 
is part of the article is unavoidably postponed till the January number, as it was 
found necessary to illustrate it with two steel plates which could not be engraved in 
time for the present number. | 
ON THE CRUSTACEANS AND Insrcrs. By A. S. PACKARD, JR. 
Representatives of all the grand divisions of the Insects and 
Crustaceans have been found in this cave, and if no worms have 
yet been detected, one or more species would undoubtedly reward 
a thorough search. ` 
We will enumerate what have been found, beginning with the 
higher forms. No Hymenoptera (bees, wasps, and ants) or Lepi- 
doptera (moths) are yet recorded as being peculiar to caves. The 
Diptera (flies) are represented by two species, one of Anthomyia 
(Fig. 122), or a closely allied genus, and the second belonging to 
the singular and interesting genus Phora (Fig. 123). The species 
of Anthomyia usually frequent flowers ; the larvae live in decaying 
vegetable matter, or, like the onion fly, attack healthy roots. It 
would be presumptuous in the writer to attempt to describe these 
orms without collections of species from the neighborhood of the 
