V0 188^ n '] 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 latter keep away from the former, though 

 she had not noticed the crayfish catching or eating them. There was nothiug to 

 prevent the crayfish ascending the stream to where the others were. 



On my first visit, the water heing 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 hoth 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 floatiug 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 tbe weaker being left behind, or some may have been swept 

 away by the torrent. The sensitive creatures would soon die in the light aud heat 

 outside, where the water is full of frogs and eyed-cray fishes. * * * 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 

 suulight. 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 80 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, bat never dry out entirely, as is the 

 case with a cave spring near by, about 1*2 feet above the level of the creek. The 

 temperatures taken in the wells at low water rauged from -)-52 u 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, tbe young of G. 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. virilia~\ of the same size. 



