PEEFACE. 



"TN bringing this publication to what I trust will prove, under the 

 circumstances, a fitting close, it is at once a pleasure and a duty to 

 express my gratitude to the various persons and bodies whose assistance 

 has alone rendered it possible to achieve a worthy production. It is no 

 part of my business to justify this method of publication of zoological 

 results. It is cei'tainly open to criticism and has, in fact, already received 

 a measure of it. It is sufficient for me to know tliat it is finished and 

 to record my deep appreciation of the courtesy with which the Pitt Press 

 have met my repeated demands up(in their consideration. The coloured 

 plates which illustrate my contribution to the natural history of the Pearly 

 Nautilus have been covered by a grant from the Publication Committee 

 of the Royal Society. 



My work on Nautilus has been carried out in all kinds of places on 

 shore and aboard ship. I was not able to bring it to a conclusion before 

 my privileges at Cambridge lapsed and I continued it in the Biological 

 Laboratory at Guy's Hospital, where I I'eceived valued assistance from my 

 colleague, Dr T. G. Stevens, F.R.C.S. 



The final touches, which always involve the heaviest labour, have been 

 largely added at the British (Natural History) Museum Ijy special per- 

 mission of the Director, Professor E. Ray Lankester. 



I have also been made free of the Research Laboratory in the 

 Zoological Department at University College, London, by permission o\' 

 Professor E. A. Minchin. 



Finally I am under a particular obligation to Mr A. E. Shipley in 

 his triple capacity of Syndic, Contributor and Friend. 



ARTHUR W1LT>KY 



GcLF OP Lions, 

 May Ut, 1902. 



