FORMERLY FELLOW AND TUTOR OF WORCESTER COLLEGE, OXFORD "THE CHALLENGER AMPHIPODA' ETC. WITH NUMEROUS ILLUSTRATIONS LONDON KEGAN PAUL, TRENCH, TRÜBNER & CO. LTD. PATERNOSTER HOUSE, CHARING CROSS ROAD 1893 PREFACE THE ambition of this volume is that it shall be one to which beginners in the subject will naturally have recourse, and one which experienced observers may willingly keep at hand for refreshment of the memory and ready reference. An attempt has been made in it to bring the reader face to face with the vastness of the theme, to show him how variously it may engage the human mind, and to give him a groundwork of information as to the objects to be examined, with a side glance at the literature that has discussed them. It is not very generally known that the species of Crustacea extend to a number of several thousands, and that some of these species people parts of the ocean in enormous swarms. Of some of the groups the general character is familiar to every one, but there are also groups of which most persons either know nothing or have not the least idea that they belong to the Crustacea. The beginner, therefore, will have provinces of a new world opened to his exploration. There is curiosity to be gratified. The sporting instinct will discover many an unexhausted territory. In the manners and customs of the creatures there is much to afford entertainment, and almost every new observer finds something singular to relate. In examining the structure both external and internal, whether in new species or in those that have been long established, the acutest powers of observation may be trained and profitably employed. Moreover, the highest ingenuity is excited and finds scope in the effort to explain the meaning of the facts observed. For, judging by discoveries already made, we are warranted in supposing that, down to the finest hair, every detail of every organism has its motive and meaning. Nor need man despair of finding out something for his private and personal benefit while investigating the physiology of a shrimp. It is needless to insist that a hundred volumes such as the present would not suffice to discuss the subject in all its bearings, since a hundred volumes would be but a small fraction of what has been already written upon it, and the incessant stream of publications widens and deepens as it flows. By the references made to some of the most recent and to some of the most important authorities, the student will be guided in general to adequate lists of literature. In consulting these bibliographical notices he will be perhaps as much amazed by the multitude of writers and writings as at first by the multitude of the genera and species of the Crustacea themselves. He will be led to consider it not unreasonable that the present volume should have been content to deal with one half of the entire class, leaving the other half for a future occasion. He will recognise by a perusal of the mere titles of what has been written, that no manual of this size could cope with all the branches of the subject, without the certainty of becoming a dry and repulsive catalogue. Even in what has been here laboriously put together the gentle reader is requested to remember that definitions are like the sermon which the preacher was forced to deliver, but to which, he reminded his hearers, they were under no sort of compulsion to listen. A time comes to the student when he scans every word of a definition with eager interest, but till then it will do him no harm to pass it. over with cursory eyes and a light heart. In a volume of the International Series it would have been inappropriate to devote to the British fauna more than its proportional space, but I have thought that it would be neither unfair nor uninteresting to mention at least the names of all the British species, so far as it has been possible for me to collect them from and correct them by the latest and best authorities. One personal matter remains to be noticed. It was long the intention of Dr. Henry Woodward, of the British Museum, to publish in this Series a ' History of Recent and Fossil Crustacea.' The continual pressure of other engagements has prevented him from accomplishing the congenial task. That, nevertheless, the results of his unrivalled knowledge of the extinct forms will sooner or later be gathered into a compendium for general use should be taken for granted. The other materials which he had collected for his purposed work, relating principally to the characters of the living organism, are still in reserve |