Seaside Studies in Natural History Marine Animals of Massachusetts Bay. Radiates.   By: Elizabeth Cabot Cary Agassiz (1822-1907)

IN

NATURAL HISTORY.

BY

ELIZABETH C. AGASSIZ

AND

ALEXANDER AGASSIZ.

MARINE ANIMALS OF MASSACHUSETTS BAY.

RADIATES.

[Illustration]

BOSTON: JAMES R. OSGOOD AND COMPANY, LATE TICKNOR & FIELDS, AND FIELDS, OSGOOD, & CO.

1871.

Entered according to Act of Congress, in the year 1865, by A L E X A N D E R A G A S S I Z, in the Clerk's Office of the District Court for the District of Massachusetts.

UNIVERSITY PRESS: WELCH, BIGELOW, AND COMPANY, CAMBRIDGE.

THIS LITTLE BOOK IS AFFECTIONATELY DEDICATED BY THE AUTHORS TO PROFESSOR L. AGASSIZ, WHOSE PRINCIPLES OF CLASSIFICATION HAVE BEEN THE MAIN GUIDE IN ITS PREPARATION.

PREFACE.

This volume is published with the hope of supplying a want often expressed for some seaside book of a popular character, describing the marine animals common to our shores. There are many English books of this kind; but they relate chiefly to the animals of Great Britain, and can only have a general bearing on those of our own coast, which are for the most part specifically different from their European relatives. While keeping this object in view, an attempt has also been made to present the facts in such a connection, with reference to principles of science and to classification, as will give it in some sort the character of a manual of Natural History, in the hope of making it useful not only to the general reader, but also to teachers and to persons desirous of obtaining a more intimate knowledge of the subjects discussed in it. With this purpose, although nearly all the illustrations are taken from among the most common inhabitants of our bay, a few have been added from other localities in order to fill out this little sketch of Radiates, and render it, as far as is possible within such limits, a complete picture of the type.

A few words of explanation are necessary with reference to the joint authorship of the book. The drawings and the investigations, where they are not referred to other observers, have been made by MR. A. AGASSIZ, the illustrations having been taken, with very few exceptions, from nature, in order to represent the animals, as far as possible, in their natural attitudes; and the text has been written by MRS. L. AGASSIZ, with the assistance of MR. A. AGASSIZ's notes and explanations.

CAMBRIDGE, May, 1865.

NOTE.

This second edition is a mere reprint of the first. A few mistakes accidentally overlooked have been corrected; an explanation of the abbreviations of the names of writers used after the scientific names has been added, as well as a list of the wood cuts. The changes which have taken place in the opinions of scientific men with regard to the distribution of animal life in the ocean have been duly noticed in their appropriate place, but no attempt has been made to incorporate more important additions which the progress of our knowledge of Radiates may require hereafter.

CAMBRIDGE, January, 1871.

CONTENTS.

PAGE

ON RADIATES IN GENERAL 1

GENERAL SKETCH OF THE POLYPS 5

ACTINOIDS 7

MADREPORIANS 16

HALCYONOIDS 19

GENERAL SKETCH OF ACALEPHS 21

CTENOPHORÆ 26

EMBRYOLOGY OF CTENOPHORÆ 34

DISCOPHORÆ 37

HYDROIDS 49

MODE OF CATCHING JELLY FISHES 85

ECHINODERMS 91

HOLOTHURIANS 95

ECHINOIDS 101

STAR FISHES 108

OPHIURANS 115

CRINOIDS 120

EMBRYOLOGY OF ECHINODERMS 123

DISTRIBUTION OF LIFE IN THE OCEAN 141

SYSTEMATIC TABLE 152

INDEX 154