ABBREVIATIONS OF THE NAMES OF AUTHORS.
| Ag. | L. Agassiz. | Jaeg. | Jaeger. | |
| A. Ag. | A. Agassiz. | Lam. | Lamarck. | |
| Ayres | W. O. Ayres. | Lamx. | Lamouroux. | |
| Blainv. | Blainville. | Lin. | Linnæus. | |
| Bosc | Bosc. | Lym. | Lyman. | |
| Br. | Brandt. | M. & T. | Müller and Troschel. | |
| Clark | H. J. Clark. | Mill. | Miller. | |
| Cuv. | Cuvier. | Pér. et Les. | Péron and Lesueur. | |
| D. & K. | Düben and Koren. | Sars | M. Sars. | |
| Edw. | Milne-Edwards. | Stimp. | Stimpson. | |
| Forbes | Edw. Forbes. | Til. | Tilesius. | |
| Gray | J. E. Gray. |
MARINE ANIMALS OF MASSACHUSETTS BAY.
ON RADIATES IN GENERAL.
It is perhaps not strange that the Radiates, a type of animals whose home is in the sea, many of whom are so diminutive in size, and so light and evanescent in substance, that they are hardly to be distinguished from the element in which they live, should have been among the last to attract the attention of naturalists. Neither is it surprising to those who know something of the history of these animals, that when the investigation of their structure was once begun, when some insight was gained into their complex life, their association in fixed or floating communities, their wonderful processes of development uniting the most dissimilar individuals in one and the same cycle of growth, their study should have become one of the most fascinating pursuits of modern science, and have engaged the attention of some of the most original investigators during the last half century. It is true that from the earliest days of Natural History, the more conspicuous and easily accessible of these animals attracted notice and found their way into the scientific works of the time. Even Aristotle describes some of them under the names of Acalephæ and Knidæ, and later observers have added something, here and there, to our knowledge on the subject; but it is only within the last fifty years that their complicated history has been unravelled, and the facts concerning them presented in their true connection.
Among the earlier writers on this subject we are most indebted to Rondelet, in the sixteenth century, who includes some account of the Radiates, in his work on the marine animals of the Mediterranean. His position as Professor in the University at Montpelier gave him an admirable opportunity, of which he availed himself to the utmost, for carrying out his investigations in this direction. Seba and Klein, two naturalists in the North of Europe, also published at about this time numerous illustrations of marine animals, including Radiates. But in all these works we find only drawings and descriptions of the animals, without any attempt to classify them according to common structural features. In 1776, O. F. Müller, in a work on the marine and terrestrial faunæ of Denmark, gave some admirable figures of Radiates, several of which are identical with those found on our own coast. Cavolini also in his investigations on the lower marine animals of the Mediterranean, and Ellis in his work upon those of the British coast, did much during the latter half of the past century to enlarge our knowledge of them.