JUN 14 1899 [ 36- J 



On the Fauna and Bottom-Deposits near the Thirty- 

 Fathom Line from the Eddystone Grounds 

 to Start Point. 



By 



E. J. Allen, B.Sc. 



Director of the Plymouth Laboratory. 



With Charts I. to XVL 



INDEX OF CONTENTS. 



SECTION PAGE 



I. Introduction . . . . . ... 365 



II. The Causes which Influence the Distribution of Life on the Sea-bottom . . 368 



III. The Physical Conditions prevailing on tlie Grounds investigated . . 374 



IV. The Bottom -deposits . . . . ... 377 



Determination of the Amount of Carbonate of Lime in the samples of 

 Bottom-deposit, and Description of their Geological Features. By 



R. H. Worth . . . . ... 381 



V. Description of the Grounds investigated . . ... 387 



VI. The Distribution of Particular Species on the Grounds under investigation . 440 

 VII. General Considerations — 



1. The Association of Species with one another . ... 514 



2. Geographical Distribution . . . . . . 519 



Tables . . . . . . ... 521 



Literature . . . . . . ... 537 



Section I. 



INTRODUCTION. 



The investigation described in the present paper was commenced in 

 1895, with the aid of a grant of £100 from the Government Grant 

 Committee of the Eoyal Society to meet the expenses of boat-hire, 

 and a further grant of £25 has been made by the Society to assist in 

 the production of the charts by which the paper is illustrated. The 

 object of the investigation has been to gain an accurate knowledge of 

 the distribution of the fauna on the sea-bottom over a continuous area, 

 in order to ascertain and where possible to explain the changes which 

 take place in the animal population when the nature of the bottom- 

 deposit changes. At the same time it was hoped that fresh light would 

 be thrown upon the general question of the distribution of life on the 

 sea-bottom and the principles upon which it depends. It appeared 

 that an investigation of this character gave promise of serving the 



NEW SERIES. — VOL. V. NO. 4. .U'.NE, 1899. 2 B 



