PREFACE 
THE manuscript of Dr. Pelseneer’s volume on the Mollusca— 
now published—was completed nearly two years ago. It has 
been translated and revised for press by Dr. Gilbert Bourne, 
of New College, Oxford, to whom the thanks of both the 
author and editor are due and are cordially tendered. 
EK. RAY LANKESTER. 
December 1905. 
