624 



REPORT OF STATE GEOLOGIST. 



The membranes are thinner and paler than in lucifugus, but in 

 all other respects similar. Calcar longer, more slender and ending 

 indistinctly in the membrane. 



Measurements. — Average of ten from Mitchell: Total length, 

 87.9 mm. (3^/2 in.) ; tail, 37.6 mm. (II/2 in.) ; hind foot, 9.9. mm. 

 (6/16 in.) ; forearm, 37.6 mm. (11/2 in.) ; tibia, 17.4 mm. (11/16 

 in.) ; ear, 12.7 mm. (% in.). 



Skull and teeth. — The differences in the skulls of the two species 

 are sufficiently characterized under M. lucifugus. Average meas- 

 urements of ten individuals from Mitchell: Greatest length, 15.3 

 mm. 10/16 in.) ; length of palate, 7.3 mm. (5/16 in.) ; maxillary 

 tooth row, 7.3 mm. (5/16 in.) ; greatest width of braincase, 7.1 mm. 

 (5/16 in.) ; depth of braincase over audital bulla, 7.4 mm. (5/16 

 in.). 



Range. — Myotis suhulatus is found over practically the whole 

 of North America east of the Rocky Mountains. In Indiana it oc- 

 curs throughout the State, but is much less abundant than the pre- 

 ceding species. In the caves I have explored, I have found the pro-, 

 portion to be about one of this species to 20 of M. lucifugus. 



Habits. — The present species, like the preceding one, is a cave 

 inhabiting bat. In most of the published records of this State the 

 common cave bat is erroneously called Myotis suhulatus. As a mat- 

 ter of fact, the records are for lucifugus, while the present species 

 has been entirely overlooked because of its close resemblance to its 

 congener. 



The habits of the two species are very similar and the state- • 

 ments made above as to food, breeding habits and relation to man 

 apply, as far as known, with equal force to both. The Say bat 

 begins to return to the eaves earlier than the little brown bat, 

 and outnumbered the latter in the Shawnee cave during August, 

 1907. In captivity the present species appears to be somewhat the 

 more active and intelligent. 



The ability of all of the cave inhabiting species to find their way 

 through the tortuous passages of the caves where darkness is abso- 

 lute, is one of the most remarkable things to be found in the mental 

 makeup of animal. Experiments made by the author show that 

 they do not depend upon sight for guidance. The animals were 

 able to avoid wires stretched in a room, as well when the eyes were 

 covered as when open. Removing the external ears was also without 

 effect. But when the auditory meatus was stopped, their ability to 

 avoid obstacles was greatly diminished. Covering the body hairs 



