F. M. Kindle — Bottom Control of Marine Faunas. 449 



Akt. XXXII. — Bottom Control of Marine Faunas as Illus- 

 trated by Dredging in the Bay of Fundy • * by E. M. 

 Kindle. 



Introduction. 



The influence exercised by the physical character of bottom 

 materials on the composition of the marine faunas living upon 

 them, has appeared so evident to many paleontologists, that it 

 is generally assumed or taken for granted by them. Others 

 have held that the character of the bottom materials had little 

 or no influence in determining the composition and distribu- 

 tion of the faunas to which they furnish a habitat. It is for 

 various and obvious reasons much more difficult to secure con- 

 clusive evidence from fossil faunas and consolidated sediments 

 for either opinion, than it is to obtain convincing evidence 

 from a study of living marine faunas. An examination of the 

 papers of zoologists who have enjoyed a large experience in 

 collecting marine molluscs will show that, without exception, 

 they recognize in the physical characteristics of the sea bottom 

 materials a potent factor in determining the abundance and 

 kind of bottom life. Concerning this point Dr. F. B. Sumner 

 writes as follows : 



"Foremost among the conditions determining the distribu- 

 tion of the bottom-dwelling organisms, we have found to be the 

 character of the bottom considered chiefly in relation to its 

 physical texture." f 



The dredging operations on which such conclusions as these 

 rest, however, have seldom been undertaken for the purpose of 

 estimating the influence and importance of this factor. The 

 discovery and description of new species has generally been for 

 the zoologist too absorbing a subject to permit him to give 

 more than secondary consideration to problems involving the 

 influence of environment on bottom life. It has seemed to the 

 writer that collections of marine invertebrates which were 

 made primarily for the purpose of ascertaining in a limited 

 area the influence of bottom environment on the distribution 

 and association of the forms of life met with, would be instruc- 

 tive alike to the zoologist and the paleontologist. Dredging 

 for this purpose was undertaken by the writer during the 

 summer of 1914 on the west coast of JSTova Scotia. Mr. E. J. 

 Whittaker assisted in this work. The dredging and collecting 

 stations occupied were with one exception in the Minas Basin 

 and Digby Bay. Their precise location, relation to low tide 



* Published with permission of the Director of the Geological Survey of 

 Canada. 

 f Bull. Bureau of Fish, U. S., vol. xxviii, p. 1229, 1908. 



