22 
GENERAL REMARKS ON CAVE FAUNA. 
able vigorously to discriminate between the two. We shall ac- 
cordingi}^ look upon the subterranean fauna, or more properly 
faunas, as small ramifications which have penetrated into the earth 
from the geographically-limited faunas of the adjacent regions ; 
and which, as they extended themselves into darkness, have been 
accommodated to surrounding circumstances. Animals not far re- 
mote from the ordinary forms, prepare the transition from light to 
darkness. Next follow those that are constructed for twilight; 
and last of all those destined for total darkness, and whose struc- 
ture is quite peculiar. Among these some are adapted for special 
localities, those which inhabit dry localities or detached little 
reservoirs being totally blind, while others, destined for running 
streams, havQ eyes of imperfect construction, so as to receive the 
impression of rays of light, but no proper image of illuminated 
objects. We may therefore with tolerable precision arrange the 
inhabitants of caverns under the following heads : — 
Shade animals. — Extensive genera and species inhabiting cav- 
erns near their entrance, and, generally, all cool, shady and moist 
localities. Of these, those that fly occasionally enter far into the 
caverns ( Diptera) . 
Ttoilight animals. — They belong to widely spread genera, but 
are peculiar to the caves, and distinguished by their small eyes. 
They are principally found near the entrances to the caves, but 
proceed deeper into the darkness than the shade-animals, and 
although wingless, they penetrate often the whole extent of the 
dark space. — {Fri stony elms elegans, Homalota spelcea.) 
Cave animals. — They form, at least in part, peculiar genera, are 
wingless and colorless, as far as the consistency of their integu- 
ments will admit, and exist exclusively in total darkness. The 
terrestrial division is blind ; the aquatic has a perception of light. 
To this group belong all the animals in the Mammoth Cave, and 
among those of the caves of Carniola, Anophthalmus, Bathyseia, 
perhaps likewise Anurophorus and Hypochthon, which, however, 
may belong to the following group. 
Stalactite cave animals. — Insects, Arachnidans and Crustaceans 
appertaining to peculiar genera, wingless, blind, brightly colored 
according to the nature of their integuments, either light brown, 
yellowish white, or snow white, perhaps according to the pre- 
ponderance of the chitine ; living in total darkness, peculiar to 
stalactite caves, in part occupying the columns and constructed 
accordingly, either for ascent or hovering over them. Here belong 
most of the animals treated of in this memoir — Stagobius, Blo- 
thrus, Stalita, Niphargus, and Titanethes.” * 
A pertinent question arises as to the time of the formation of 
these caves and when Lhey became inhabitable. As previously stat- 
a note appended he adds to the list “a new cave crustacean, Patomon anopthal- 
mus Kollar, said to serve as food for Hypochthon [the Salamander], of which last genus 
he discriminates six species.” 
