FROM TUE EDDYSTONE GROUNDS TO START POINT. 367 



depths there appears to be little change in the fauna at different times 

 of the year, excepting in the case of the migratory fishes. 



In the identification of the species I have received very great assist- 

 ance from my colleagues, as well as from many naturalists who have 

 from time to time worked in the Laboratory, and without this assistance 

 it would have been impossible to have attempted to give so full an 

 account of the fauna of the grounds as I am now able to do. I would 

 therefore express my great indebtedness to Prof. Weldon, Messrs. W. 

 Garstang, E. W. L. Holt, T. V. Hodgson, E. T. Browne, W. I. Beaumont, 

 T. H. liiches, and T. H. Taylor for the help which has been so readily 

 given. The particular groups in which each naturalist has assisted will 

 be found mentioned in Section VI. It must be understood, however, 

 that the responsibility for the statement that a species occurs upon any 

 particular ground is in all cases my own. 



My thanks are also due to Mr. E. H. Worth for the geological ex- 

 amination of the samples of bottom-deposits, and for the determination 

 of the amounts of carbonate of lime which they contain. Mr. Worth's 

 principal contribution will be found at page 381 : others are enclosed in 

 square brackets, and are followed by his initials. 



With regard to the names adopted for the different species, my one 

 object has been to make my meaning understood as readily as possible. 

 For most of the groups therefore some standard monograph has been 

 made use of, the name of which is stated in each case, and the nomen- 

 clature there given has been employed. In a few cases old and well- 

 established names have been retained in place of later but less known 

 ones. 



It will, I think, be clear to anyone studying the results of this 

 investigation that information of great value would result from a 

 comparison of the faunas of these grounds with those found in similar 

 situations around the British coasts. Although a great deal of dredging 

 has been done, very little information has as yet been published in a 

 form available for making such comparisons, and as will be again 

 pointed out (see p. 377), the accounts of the nature and texture of the 

 bottom-deposit require to be much more definite and detailed than those 

 which have generally been given. 



Even when one seeks for knowledge of the true centre of distribution 

 of a species, either of its geographical or of its bathymetric distribution, 

 it is remarkable in how few instances this can be ascertained from the 

 published accounts. If we are ever to obtain an accurate knowledge 

 of the adaptation of species to their environment they must be studied 

 at their centres of distribution, in those localities where they are 

 exceptionally abundant, for it is there that the species is kept true, and 

 it is to the conditions there prevailing that the species is most perfectly 



