1917] Mead: Notes on Enierita Analoga 437 



narrow range of stimuli and restricted habitat the range of intensity 

 of stimuli to which they respond is comparatively narrow. If the 

 intensity of a certain stimulus transcends the limits of this narrow 

 range no response follows. This seems to explain the frequent in- 

 disposition or death of the animals during a series of experiments. 



SUMMARY 



1. Emerita analoga lives in the wave-washed parts of the sandy 

 beaches of California. 



2. The animals tend (1) to run down slopes, and (2) to go towards 

 the ocean, when within 200 feet at least of it, although their view of 

 the ocean be intercepted. 



3. A 7 per cent slope away from the ocean neutralizes their ocean- 

 ward tendency. 



4. Experiments in the air with Emerita analoga cannot be con- 

 tinued for many hours with normal responses. 



5. Emerita analoga is noticeably limited in its habitat, and the 

 range of intensity of stimuli to which it responds is comparatively 

 limited. 



ACKNOWLEDGMENTS 



I am greatly indebted to Mr. Percy S. Barnhart for the use of an 

 unpublished article bj^ him on analoga, and for valuable assistance 

 in looking up literature, and also to Dr. W. E. Ritter for many 

 helpful suggestions. 



Transjnitted January IS, 1917. 



