SENSORY ADAPTATIONS OF BATS. 143 



inform me that they are never seen in the inner parts of the cave 

 — probably not more than a mile from the entrance. 



Marengo and Wyandotte Caves were visited in July, 1907. 

 Bats never occur in large numbers in the former, perhaps because 

 a building has been erected over the entrance. On the occasion 

 of my visit two were seen, one of them flying, in Mammoth Hall, 

 the other clinging to the wall in the Pillared Palace. In Wyan- 

 dotte Cave the bats congregate in enormous numbers during the 

 winter. At the time of my visit in summer only a few were seen. 

 Blatchley ('96) states that they reach the innermost recesses of 

 this cave in winter, but gives no localities at which they were 

 seen beyond Crawfish Spring, about two miles from the entrance. 

 The same authority states that he took 401 bats, by actual count, 

 from a space one by one and seven tenths feet square, on a low 

 ceiling in Saltpeter Cave, Crawford County, Indiana. 



In the caves of the Donaldson Farm they have been found 

 throughout all of the explored portions, which, in the Upper 

 Spring Cave, extend more than a mile from any known opening. 

 The smaller caves about Bloomington have been visited at inter- 

 vals throughout the year. In Mayfield's Cave, four and one half 

 miles northwest of Bloomington, the relative abundance of the 

 two most common species is reversed. Banta ('07) states that 

 P. siibflainis is fairly abundant while M. hicifugus was seen only 

 three or four times during three years' observation of the cave. 

 I visited the place January ii, 1907, and December 21 of the 

 same year, and confirmed his observations, finding 17 of the first 

 species and 2 of the second on my first visit and 22 and 3 

 respectively at the second visit. 



P. siibflavns was more abundant also in Strong's Cave one 

 mile from Mayfield's, during the winter of 1907-8. In Truitt's 

 Cave, 2y^ miles from Mayfield's, and considerably larger, there 

 were 40 P. siibflavus and 5 i M. lucifugiis on November 29, 1907. 

 In Coon Cave, 2 miles from Truitt's and 4 ^ from Mayfield's, there 

 were about 500 bats on March 29, 1908, not more than 50 of 

 which were P. subflainis. Two M. subnlatns were seen and a few 

 others may have been overlooked ; the others were M. hicifugus. 

 Eller's Cave, visited on the same day as Coon, was inhabited by 

 about 100 bats. Approximately nine tenths of them were M. 

 hicifugus and the remainder P. subflavus. 



