4 
MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
tera by Baron Osten Sacken, and the only Psocidse found have been described, so far as they 
could be, by Dr. Hagen, 
In 1880 I visited the New Market and Luray caverns. Mr, H. G. Hubbard has kindly loaned 
me many of the specimens which he collected in Mammoth Gave. The entire collection of cave 
insects, excepting some of the duplicates, embracing the types obtained by Mr. Sanborn and 
myself while attached to the Kentucky geological survey, have been placed in the Museum of 
Comparative Zoology at Cambridge, Massachusetts. J ^ •>- -*'My 
I. DESCRIPTION OF THE BETTER-KNOWN CAVES. 
MAMMOTH CAVE. 
As Mammoth Cave is the largest and most frequented, and was the first known to contain eye* 
less animals, we will first briefly describe this great cavern, simply dwelling on those points which 
are of interest from a biological point of view. One can form little idea of the general geological 
relations of this cave from a few visits, especially when busied with the search for cave animals; 
and we are indebted to the Kentucky geological reports, containing accounts by Professors Owen 
and Shaler, also to an excellent paper by Mr. \V. Le Conte-Stevens, 1 and the carefully-prepared 
work of Rev. H. C. Hovey on “ Celebrated American Caverns,” who has given the results of much 
time spent in exploration, and has taken, with more care than any one else, the temperatures of 
this 1 aud other caves. By consulting Mr. Hovey’s map of the cave 2 and reading Mr. Stevens’s 
condensed account, aided by his sketches, we can obtain a fair idea of the topography of the cave, 
embracing the dry and damp portions; i. e., those portions not deserted, and those most frequented 
by the animals of the caves. 
Mammoth Cave is situated in latitude 37° 14' N., and longitude 86° 12' W., in Edmondson 
county, Kentucky. It is the largest out of five hundred caverns estimated to exist in this county. 
These caves are excavated in the subcarboniferous limestone, covering a more or less elevated 
area, estimated to be 8,000 square miles in extent, and varying in thickness from 10 to 300 or 400 
feet. This plateau is so honey-combed, that the drainage is almost entirely subterranean. The 
general features of this limestone table-land are paralleled by those of the less extensive Carniolan 
caves, described as follows, in Geikie’s Elementary Lessons in Physical Geography (p. 246-247). 
One of the most remarkable examples of this kind of scenery is that of the Karst, in Carniola, on the flanks of 
the Julian Alps. It is a table-laud of limestone, so full of holes as to resemble a sponge. All the rain which falls 
upon it is at once swallowed up and disappears in underground channels, where, as it rushes among the rocks, it can 
he heard even from the surface. Some of the holes which open upon the surface lead downward for several hundred 
feet. Some turn aside and pass into tunnels, in which the collected waters move along as large and rapid subter¬ 
ranean rivers, either gushing out like the Timao at the outer edge of the table-land, or actually passing for some 
distance beyond the shore, and finding an outlet below the sea. Here and there the labyrinths of the honey-combed 
rock expand into a vast chamber with stalactites of snowy crystalline lime hanging from the roof or connecting it 
by massive pillars and partitions with the floor. Such is the famous grotto of Adelsberg near Trieste—a series of 
caverns and passages with a river running across them.” 
Stevens states that the subcarboniferous limestone in which the Mammoth Cave is situated is 
overlaid with a thin stratum, mostly of sandstone, which is pierced by thousands of sink-holes, 
through which the surface drainage is carried down into limestone fissures and thus to the general 
drainage level of the Green River. “ This stream passes at the distance of less than a mile from 
the Cave Hotel, the floor of the latter being 312 feet above the water and 118 feet above the mouth 
of the cave.” He adds: u The rate of erosion in the Mammoth Cave has been variable. The older 
parts are perfectly dry, and entirely free from stalagmitic deposits, indicating rapid erosion, fol¬ 
lowed by elevation, so as to deviate the water completely into other channels. In the newer parts 
the water is still dripping from the surface above, and depositing stalactites and stalagmites.” It 
is in the newer damper parts, as well as in or near the subterranean streams and pools of this and 
most if not all the other caves that the animal life mostly congregates. It will be seen that the 
caves have frequent passages communicating with the upper world, and it will also be seen how 
1 For the titles of these articles see Chapter X, Bibliography. 
3 Kindly loaned by the publishers, Robert Clarke & Co., Cincinnati. 
