74 



BLIND VERTEBRATES AND THEIR EYES. 



The author has also taken this species in a small cave at the edge of the town 

 of Glasgow, Kentucky, where it is moderately abundant and easily accessible, but 

 on account of the limited extent of the environment very few were caught on any 

 one trip. One was found under a floating board in this cave. One other speci- 

 men was secured after an extensive exploration on foot and on hands and knees 

 in a cave at Cave City, Kentucky. 



Typhlichthys osborni Eigenmann. 

 Typhlichthys osborni, Eigenmann, Biol. Bull., vm, p. 63, Horse Cave, Ky. 



Typhlichthys osborni is known only from Horse Cave, Kentucky. The town 

 of Horse Cave is situated at the junction of two intersecting valleys. Their streams 



Fig. 20. (a) Side and (b) Dorsal View of Head of Typhlichthys osborni. 



have long ago disappeared from the surface and now flow 185 feet beneath the city. 

 In the heart of the town is a sink or depression with vertical walls which was prob- 

 ably caused by the falling of the roof of a large cavern. At one end of the sink an 

 inclined plane leads into the underground stream, which supplies the city with 

 water. The stream also furnishes the power to light the city. A dam across the 

 cave furnishes the head for the power, but so modifies the conditions above it as 

 to make collecting practically impossible. A convenient break in the dam made 



