eo | PROCEEDINGS OF THE NATIONAL MUSEUM. 627 
Miss Wilson, who was with me, thinks the crayfish devour the others. She has 
never seen them together, and says the Jatter keep away from the former, though 
she had not noticed the crayfish catching or eating them. There was nothing to 
prevent the crayfish ascending the stream to where the others were. 
*¥ * * *¥ * * * 
On my first visit, the water being low, no crayfish were seen in the dark nook, the 
place favored by the fish. After the storm which had flooded the caves, a few were 
found there. Though I watched for some time, I never saw them pursue the fishes, 
as they might easily have done, guided by the stir in the water. Both creatures are 
very sensitive to the slightest ripple. During high water a pool, ‘‘the lake,” is 
formed a little way from the stream in another dark part of this cave. In low water 
the pool is cut off from the creek. I found both species in it, the fish in the darkest 
part, and saw no signs of enmity. Most of the crayfish were found in the lower part 
of the stream, in the twilight; the fishes could not be found without the lantern. 
At the time of the floods the cave is full, and the water rushes out furiously. * * * 
Another proof that the crayfish are more fond of the light is seen in the shallower 
wells. That from which most were taken was more exposed to the sun. At noon, 
when the light was more favorable, we could see them swimming about. No fishes 
have been taken from this well. They were taken in the narrower, more shaded 
wells, of which the deep ones on the hills report fishes only. 
As to the food of the fishes, I discovered nothing. The mud where they were was 
not so deep as farther down. An examination of it the length of the cave brought 
to light many snails; the shells of the living ones are whiter and more nearly 
transparent than the floating dead ones. The largest crayfish are of a dirty rusty 
color, and very bristly, in caves and in wells. One large one is very soft and very 
white; no doubt it is newly moulted. 
Both fish and crayfish were less numerous after the freshet, and apparently less 
active. The disturbance of the flood may have caused them to retreat into their 
hiding places, only the weaker being left behind, or some may have been swept 
away by the torrent. The sensitive creatures would soon die in the light and heat 
outside, where the water is full of frogs and eyed-crayfishes. * * * The speci- 
mens became opaque when they are put into alcohol; they are almost transparent 
when alive, so much so that the action of their internal organs can be observed. 
Repeated tests assured me the animals were blind, though very sensitive to the 
sunlight. They died soon after catching, even in water frequently changed. 
The wells from which specimens have been taken are about half a mile from Cen- 
ter Creek, the water level in wells and creeks being nearly the same. The wells 
were nine or ten in number, from 5 to 30 rods apart, from 11 to 30 feet in depth, 
deeper in the higher ground, and having a depth of water varying from 2 to 4 feet. 
In some wells the rock at the bottom had been excavated. The water is what is 
commonly called hard, i. e. impregnated with lime. After rains some of the wells 
have softer water than others, and the water stands higher in these wells, indicating 
closer connection with surface drainage. All of the wells soon regain the common 
level. They become low in times of drouth, but never dry out entirely, as is the 
ease with a cave spring near by, about 12 feet above the level of the creek. The 
temperatures taken in the wells at low water ranged from +52° to 54° Fahr. 
During a storm in the well having the highest water, the temperature rose to +-57°. 
When the mercury stood at 90° to 95° in the shade outside, the temperature was only 
54° in Wilson’s Cave, 
According to Miss Hoppin, the young of C. setosus when alive are 
not so white as the older ones. 
At first I attributed it to greater transparency, but now I am sure the color is in 
the shell, not that the internal organs can be seen because of the transparent shell. 
They are not so dark, however, as the brook species [ C. virilis] of the same size. 
