VARIATIONS IN THE SHELL OF TEREDO 

 NAVALIS IN SAN FRANCISCO BAY 



EOBEET CUNNINGHAM MILLER 



CONTENTS 



PAGE 



Introduction 294 



The shell of Teredo 295 



Description 295 



Age and deposition of ridges 296 



Variability and environment :;l| l 



Ecological conditions - :!l| l 



Variation in number of ridges 306 



A : ariation in the auricle 309 



Variation in surface sculpture 31] 



Variation in color 312 



Systematic bearing of variations., 313 



Summary •'■' ' 



Literature cited 318 



Explanation of plates :: -" 



