OBSERVATIONS ON TYPHLOMOLGE RATHBUNI. 



77 



habitants claim that this creek had running water in it until about 

 50 years ago. At present only a few water holes are left in the 

 upper course of the valley and several sink holes have formed in 

 its lower course. These are filled temporarily with rain water. 

 In time of severe cloud bursts the water in the creek becomes a 



* II /''**-. 



&) ^"vi^- -'"'' 



\ r tf 



FIG. 2. Map of San Marcos Area. 



1. San Marcos. 5. Ezell's Cave. 



2. Artesian Well of U. S. Fish 6. Frank Johnson's House. 



Hatchery. 7. Frank Johnson's Well. 



3. Head of San Marcos River. 8. Swift's Cave. 



4. Beaver Cave. 



torrent rising to a height of 8 feet, but it disappears completely 

 within several hours. 1 Purgatory Creek has now become a sub- 

 terranean creek. Mr. Frank Johnson's farm is located near 

 where the creek crosses the fault line. 



i The general character of a creek like this may be found described in Hill 

 and Vaughan, page 207. 



