^^^♦»OG,4^ 1930 Gift of Emily Lowes November, 1930 In Memory of Her Husband John Lowes -\ "^ SEA-SHORE LIFE. 0t\sy $^orh 3tquarium l^aturc M^tvic^ ^umhct \ SEA-8H()RE LIFE THE INVERTEBRATES OF THE NEW YORK COAST BY ALFRED GOLDSBOROUGH MAYER Director of the Marine Biological Laboratory of the Carnegie Institution at Tortugas, Florida PUBLISHED BY THE NEW YORK ZOOLOGICAL SOCIETY 1905 COPYRIGHT 1905 NEW YORK ZOOLOGICAL SOCIETY. EDITED AND ARRANGED BY E. R. SANBORN. PRINTED BY FRANK PRESBREY CO. ADVERTISEMENT The present work is the first of the New York Aquarium Nature Series. It is designed chiefly as an aid to the study of the marine invertelDrate life of the region about New York. It will be found a valuable reference book for visitors studying the collections of the Aquarium, as the species herein considered are very largely those which may be seen there alive, from time to time. The book is a gift of tlie author to the New York Zoological Society, and the proceeds from all sales are devoted to the increase of the collections of the Aquarium. C. H. TOWNSEND, Director of the Aquariuvi. OFFICERS OF THE Ij^etD ^orh Zoological ^ocictp President HON. LEVI r. MORTON First Vice-President Second Vice-President HENRY FAIRFIELD OSBORN JOHN L. CADWALADER ©vrcutitir Committcf CHARLES T. BARNEY, Chainnnn HENRY FAIRFIELD OSBORN MADISON GRANT JOHN S. BARNES WILLIAM WHITE NILES PHILIP SCHUYLER SAMUEL THORNE LEVI P. MORTON, E.v-Offieio Secretary Trcusurer M4DIS0N GRANT PERCY R. PYNE ]1 Wall St. 52 Wall St. Director of the Zoological /'(/c^,- Director of the Aquarium WILLIAM T. HORNADAY CHARLES H. TOWNSEND lS3d St. and Soutliern Boulevard Battery Parh Slquarium Committee CHARLES H. TOWNSEND, Chairman CHARLES L. BRISTOL, University of Keic York WILLIAM E. DAMON CHARLES B. r)AVENPORT, Director Biological Lalorafory, Cold Sprinij llarhor, X. Y. BASHFORD DEAN, Cohtmhia Univer.sity ALFRED G. MAYER, Tortugas Laboratory of Carnegie Institution THOMAS H. xMORGAN, Cohnnhia I'nivrrsity ROSWELL MORSE SHURTLEFF EDMUND B, WILSON, Columbia University PREFACE nnMIS little work attempts to present in clear, untechnical lan- guage, a description, accompanied by photographs, of the larger and more conspicuous marine invertebrates of the coast of New York State. In order to increase the general usefulness of the work, however, accounts of the habits of a few creatures from other re- gions are introduced. Such are: Commercial sponges, crayfishes, the spiny lobster, the edible shrimp, the orchid land-crab, fresh- water mussels, the giant clam, the ]3earl oyster, the giant scpiid, and the chambered nautilus. A brief description of some of our common "sea squirts," or tunicates, is also given on account of their interesting position among primitive vertebrates. This work is intended for readers who may be unfamiliar Avith the technical tei'ms in use among specialists, and consequently such terms have been avoided whenever a simple English equival- ent could be substituted. Its aim is to increase intelligent interest in the habits and life- histories of our marine animals, and to disseminate a knowledge of their appearance and relationships. It is not a textbook of syste- matic zoology. It is designed to be of use to the beginner, and with the hope that a perusal of its pages may stimulate to further study, many references to works in the English language of a more thorough 10 PREFACE and pretentious character are given. We hope that it may thus serve as a stepping-stone to those whose love of nature may lead them to achieve to that greater delight in her works which can come only through long and thoughtful study of her manifold forms and wonderful ways. Lastly we hope that these pages may serve to render the col- lections of the Aquarium, and of the Natural History Museums of New York and Brooklyn more intelligible, and to aid, even if it he but little, in the educational work which it is the high mission of these institutions to perform. It gives the author sincere pleasure to express his gratitude to the authorities of the Museum of the Brooklyn Institute of Arts and Sciences in allowing him to take photographs of specimens upon exhibition within the Museum. Of the 119 figures; HI are derived from photographs of living or dead specimens, while eight are taken from hitherto unpublished illustrations. Of the illustrations ; three representing a coral reef of the Bahamas, the giant squid, and the American octopus are from paintings by Herbert B. Judy, Esq. The originals are on exhibi- tion at the Museum of the Brooklyn Institute of Arts and Sciences. Five illustrations are from drawings by the author. Of the ill photographs of animals; one, that of Sagartia leucolena was pre- sented by Mr. William F. Patterson, while the remainder were taken bv the author. CONTENTS I, Introduction II. Sponges or Porifrra . 1. Commercial Sponges IX. Crustaceans 1. Barnacles 5. Sand Fleas 2. Crayfishes C. Crabs 3. Shrimps and Prawns 7. Fiddler Crabs 4. Hermit Crabs 8. Sea Spiders X. Mollusks 1. Clams, Oysters and Mussels 2. Marine Mussels 3. Fresh-Water Mussels 4. Snails and Slugs 5. Naked Mollusks or Sea Slugs 6. Squid, Octopus and Nautilus 7. Squids or Sea-arrows XI. Tunicatks page 15 25 III. Jellyfishes and Hydroids IV. Sea Anemones and Corals V. Starfishes, Se\ Urchins and Sea Cucumbers . VI. Worms Vlt. Braciiiopods Vr[[. Moss Animals and Corallines .... '^ 30 40 49 r>2 72 ( t 113 ICG ILLUSTRATIONS. FIGURE PAGE A CoHAL Reef of the Bahamas . . . Frontispiece 1 Living CoMMEuriAi. Sponge . 26 2 Skeleton of the CoMMEiiciM, Sponge 26 3 Ret. Sponge 27 4 Red Sponge 27 5 Clam Shell infesteu with boring Sponge .... 28 6 The Finger Sponge .... 28 7 Urn Sponge 29 8 Portuguese Man-of-Wai; . . 30 9 MiLKY-wsK Jellyfish ... 33 10 Speckled .Jellyfish .... 34 11 GONIONEMUS MuRBAcnii . . 35 12 Passion-flower HyoROiD . . 36 13 Eel-grass Hydroid .... 37 14 Sea-pu ME 38 1.5 Eyed-coral 40 16 Star-coral, showing living POLYPS 41 17 Stony Skeleton OF Star-cor.vl 42 18 Fleshy Coral 12 19 Brown Sea-Anemone .... 43 20 Brown Sea- Anemone (contracted) 44 21 White-armed Anemone . . 45 22 Sand-Anemone 46 23 Cake-Anemone 48 24 Common Starfish 50 25 Horseshoe Crab, Common Star- fish AND Green Sea-Urchin 52 26 Blood-Star 54 27 Mud-Star 55 28 GLiNT Starfish 56 29 Brittle Star ...... 57 30 Basket Starfish 58 31 Purple Sea-Urcuin . , . , 58 FIGURE page 32 Sand-Doi.lar 60 33 Brittle Sea-Cucumber . . . 61 34 Ribbon-worm and Opal-worm 65 35 Sea-mouse . 65 36 Clam Worm 66 37 Red Thread Worm . . . . 67 38 Four-jawed Worm . . . 67 39 Fringed Worm . 68 40 Tufted Worm 68 41 Blood-spot Worm .... . 69 42 Dead Scallop Shell . . 70 43 Parchment Shells growing upon A STONE . 72 44 Moss- Animal 75 45 False Corai . 76 46 Young Rock-crab . . . 78 47 Rock-crab . 79 48 R(.)CK covered with Rock Bar- nacles 81 49 Deep-water Barnacles . . . 81 50 Whale Barnacle . . . . 82 52 Stalked Barnacles . . . . 82 52 American Lobster . . . . 83 53 Spiny Jjibster . 85 54 Snapping-prawn .... . 86 55 Brook Crayfish .... . 88 56 Common Shrimp .... . 89 57 SiiiuMi's AND Prawns . . . . 90 58 Southern, or Edible Shrimp 91 59 62 Hermit Crab .... 92 94 63 Little Hermit Crab . . . 94 64 Sanhbug . 95 65 Mantis Shrimp .... . 95 66 Sand Fleas . 97 67 Blue, or Edible Crab . . . 99 68 Green Crab . 100 69 fjADY Crab . 101 ILLUSTRATIONS 13 FIGURE I'AOK 70 Gui.F-wEEo Crab 101 71 JoxAH Crab; Rock Crau . . 103 72 Female Oyster Crab .... lOl 73 Ghost Crab 105 74 Fiddler Crab 105 75 BiRROws OF Fiddler Crab . 106 76 Orchid Lxm> Crab .... 107 77 Male Spider Crab; Female Si'iDER Crab; Ghost Crab; Mid Crab 109 78 ACiVNTHOPLEIRA (IRANI LATA . . Ill 79 Mussels exposed at low tide . 117 80 Americvn Oyster 122 81 Sl-rf Clam 123 82 Soft-shell Clam 124 83 LiTTLE-SECK Clam .... 125 84 Razor Clam 126 85 Sand-bar Clam 126 86 S\VIMMIN(i Cl AM 127 87 Bloody Clam 127 88 Ship Worm with siphons PliilTRITHNO 128 89 Con Clam 129 90 KlilBLE MUSSEI 130 91 Ribbed Missel 130 92 Roc K-BORINO MrssEi 131 93 Razor Shell 131 90 Co.MMON Scallop 133 96 Arctic Scallop 134 KiGi re page 97 Jingle Shell upon a rock . .135 98 Northern Sand-Collar Snail 130 99 Southern Sand-Collar Snail . 140 100 Northern Sand-Collah Snail 141 101 Knobbed Whelk; Channelled Whelk 142 102 English Whelk and Egg Cocoons 143 94 Horse MussEt 143 103 Rock Snails 144 104 Ten-ribbed Snail 145 105 Oyster Drili 146 106 Nassa Trivittata; Nassa Obso- LETA 146 107 Periwinkles clustering upon a ROCK 147 108 Periwinkle 147 109 Periwinklr; Sea-weed Snail . 148 1 10 Floating Snaii 149 111 Eel (Jrass covered with Periwinkles 150 112 Decker Shell 150 113 Octopus Americanis .... 153 114 CiiAMBEREn, OR Pearly Nai Tin s 157 115 Bllnt-tah.ed Squid .... 160 116 Gi.ANT Squid 162 117 Paper Nautilus 164 118 C'lONA Intestinai.is .... 168 119 ^[ni.GiTA ^Fanilattensis . . 170 INTRODUCTION "IV'ATURALISTS have come to believe that all of the higher animals and plants have descended from simpler forms which lived in the past; and that these in turn were derived from even simpler ancestors. Indeed, it is possible that all animate nature is the offspring of one primitive living cell which contained within itself the power of giving rise to all of the plant and animal life of our world. But although we know not how or when life originated, science has been able to make known some few of the remarkable changes which have come over animate forms under the influences of evolu- tion, and natural selection. Excellent examples of such changes are exhibited in the great Hall of Vertebrate Fossils at the American Museum of Natural History, where we may see a series of fossil skeletons which prove that the horse was once a four-toed creature hardly larger than a fox but that now it walks upon its middle toe, the side ones having disappeared. Another series of fossils shows that in Eocene times the camel was also a little four-toed creature; but nt)w there are but two toes on each foot, the side ones having disaiDpeared. A careful study of living creatures has shown that, while off- spring usually bear a close resemblance to their j^arents, a few dejDart widely from the parental types, and that some of these de- partures show a strong tendency to maintain themselves, through inheritance, for generation after generation. But this is not all, for we know that animals and plants tend to increase at a rate so enormous that, shoxild all survive, the land would soon be densely covered and the ocean completely filled with living creatures. This, however, is prevented by the constant comjDetition for life. Only those few that are able to conquer in the strife for food and space can survive, and myriads of the Aveak and unfit must perish. Whole races have succumbed to this competition. Not one of the 16 SEA-SHORE LIFE trilobites, more than 1700 species of wliich existed in the Cambrian and Silurian rocks, survives to-day ; and the sea lilies, which once grew in vast colonies along our shores, are now represented by only a few rare species in the deep ocean. The older naturalists did not realize the vastness of the destruc- tion which this baUle for life has wrought, and thought that each species was a separate creation that had existed unchanged since the beginning. We now know that species appear to be distinct one from another because the intermediate forms have died out; and the longer a once closely related group of species has existed, the wider do their differences become until we may look in vain for the "linking forms" which once connected all of them. For example, we know that the vertebrates are recent, and are descended from the far more ancient invertebrates. Accordingly, we find that there are but few breaks in the chain of forms rang- ing from the lowest fishes to the mammals. Indeed, the eml)ryos of the highest mammals display gill slits in their necks, which soon close ov-er, but which were of nse throughout life in their fish-like ancestors. When we study the invertebrates, however, we find wide gaps so that no one has yet been able to determine the rela- tionships of some of the greatest groups. For example, we can not tell how the sponges, jellyfishes, eclii- noderms or worms may be related one to another, but on the other hand we have reason for the belief that crustaceans and insects are descended from worm-like ancestors, and that moUusks may pos- sibly have had a somewhat similar origin. It is interesting to observe that we meet with the same condi- tions among plants. The algte and fungi show -wide gaps which prevent one from arranging them in any connected series, whereas the flowering plants, which are certainly more recent and have descended from non-flowering forms, can be arranged in a fairly regular chain, leading gradually from the lowest to the highest. We must bear in mind, however, that recent studies by Bate- son, de Vries and others tend to show that new species may appear suddenly as the offspring of old and well known forms; and that these new and peculiar animals or plants may, through inheritance, perpetuate their new peculiarities. There may then be no inter- mediate or "linking" forms between the old and the new species. INTRODUCTION 17 A large number of marine animals whose true home is among the Bahamas, or West Indies, are drifted upon the southern coast of Long Island by the southerly Avinds of the summer months and become quite abundant along our shores in August. From November until April, however, the northerly and easterly winds prevail, and these drift down upon us a host of creatures wdiose home is in the cold arctic water. We see then that tropical and sub-tropical animals are found along our coast in summer and early autumn, while arctic creatures live there in winter and spring. There are. however, an even greater number of creatures which are permanent residents, and are to be found with us in some stages of their lives at all seasons of the year. Many marine animals or plants thrive only between tides, and must be exposed to the air for at least an hour or two every day. Such are the barnacles, some snails, and the great masses of olive- green seaweed with gas filled cavities in its stems called Fucus. Others, such as the brown, salmon-pink, and white sea anemones (Metridium marginatum J and the common starfish ( Asterias foi-be- siij, delight in the shallow tide-pools but do not thrive if long ex- posed to the air. Great numbers of creatures live along the coast beyond the influence of the tides and find their homes among the eel-grass, under stones or mud, or roaming freely through the water. Others, such as the Portugese man-o-war fPhymliaJ, the beau- tiful, purple floating snail (Jantlnna), and a host of jellyfishes and crustaceans find themselves at home far out at sea and never come near land unless drifted along the coast by accident. Such are the creatures which even thousands of miles from land cause the ocean to glisten with brilliant flecks of phosphorescent light, if the water be agitated at night. But there are other creatures which spend their whole lives upon the bottom of the deep sea, and have been dredged from all depths down to four and one-half miles. Here they live in the ice- cold water of the depths, where the darkness is profound and where no current moves. Many of them have A-ery large eyes, or are pro- vided with remarkably long or delicate "feelers," and phosphores- cent areas upon their skins, and thus they find their way around in their cold, dark, changeless world. A considerable number of 18 • SEA-SHORE LIFE these deep-sea creatures belong to types which once liv-ed in shallow water along our coasts, but which died out long ago, and are known to us only through their fossils in the rocks. Marine animals are much more abundant along or near conti- nental coasts than in the open sea far from land, for we must bear in mind that animal life can subsist only upon plant life and that the great food supply furnished by the shallows of a shore are most favorable for the development of a varied fauna. The great ocean currents, such as the Gulf Stream in the At- lantic, and the Kuroshiwo of the Pacific are the bearers of vast hordes of floating creatures which are thus carried from the tropics far into the temperate regions. Temperature is also a great factor in determining the distribution of marine life. On our own coast, for example, Ave find that the cold arctic water creeps down the New England coast to Cape Cod, while south of that place the shore water is warmed during the summer by the drift from the Gulf Stream. Accordingly a great number of southern forms extend only as far north as Cape Cod, and similarly many of the arctic creatures can not survive in summer in the warm Avater south of that cape. It is even more interesting to see that at Cape Breton, Nova Scotia, we find a number of creatures Avhose true home is south of Cape Cod, Massachusetts, but which are able to live in the warm water at the mouth of the St. Lawrence, where the Gulf Stream approaches the coast for the last time before its final deflection into the midst of the Atlantic. So important is temperature in determining the distribution of marine life, that while the creatures of the tropical Atlantic and Pacific on opposite sides of the Globe are, broadly speaking, quite similar, those living north of Cape Cod are almost wholly different from those of the Florida coast. But the most remarkable condition is seen in the distribution of the creatures of the deep sea, for here the temperature is nearly the same everywhere, being only slightly above the freezing point. Accordingly many of these animals range from Arctic to Antarctic, and from Atlantic to Pacific. Many forms that live only in deep, cold water, south of Cape Cod come into the shallows on the Maine coast. INTRODUCTION 19 In the Arctic regions we find vast numbers of individnals of but few species, Avliereas in tlie tropics tlie individuals are little or no more numerous, bnt the number of species much greater than in cold regions. It is a mistake to assume that animals invariably become rarer as we approach the limit of their range; for example, the common scallop is very abundant in Provincetown Harbor, Cape Cod, but is all but unknown north of that place. An interesting account of the distribution of deep sea animals, and of the floating life, is given by Alexander Agassiz in "Three Cruises of the Blake," 2 vols., 1888, Bulletin of Museum of Com- parative Zoology at Harvard College ; and a very general discussion of the distribution of animals as a Avhole is given by Professor A. Heilprin in "The International Scientific Series," Vol. LVII, 1887. The study of intelligence in lower animals is a subject of fas- cinating interest. Nevertheless popular writings upon such mat- ters are usually in error, for the authors are too apt to conclude that when the actions of an animal appear "sensible" from our point of view, or evidently serve a useful purpose, they must necessarily be conscious. For example : the caterpillar of the mon- arch butterfly fDanais areltippusj feeds only upon milkweed, and is generally found upon the tender young leaves near the top of the plant, whore it is surrounded by the juiciest and most nutricious food. Experiments by the author show, however, that we can not conclude that the caterpillar exercises any conscious choice or reason in the matter, for its being there is due to two simple reac- tions. It has an inborn tendency to crawl upward rather than down- ward, and it is also strongly inclined to crawl toward the light. If one plant a milkweed in a ilower-pot, and then turn it upside-down the caterpillars will soon crawl upward toward the light of the sky, and will thus wander away from the plant and starve to death, although under normal conditions these two reactions would serve to maintain them in the best situation for obtaining food, and pre- vent their roaming away from the plant. Nagel and Parker have also shown that if we place a piece of meat upon certain of the tentacles of a sea-anemone, the meat is rapidly thrust into the mouth. If then we place a piece of paper soaked in a weak solution of meat juice it is at first swallowed, but 20 SEA-SHORE LIFE after a few trials it is invariably rejected. The tentacles on the other side of the animal will, however, conduct the paper to the mouth even after those on the side first exiDcrimented upon no longer accept it, and it is evident that the experience of one side of the animal has no effect upon the other side. It seems reasonable to assume that if an animal can be trained or can learn by exiDerience it has associative memory, and therefore must be conscious, but it is certain that sponges, jellyfishes and worms have no trace of associative memory. On the other hand Robert Yerkes has shown that the green crab can learn to travel by the shortest path through a labyrinth to its food. It is also believed that the squids and octopi, which are the highest inollusks, have associative memory. However, practically all of the instincts of marine inverte- brates are inherited, and the behavior of the animal is not altered by personal experience or association with its fellows. They re-act to external stimuli with almost machine-like regularity, and we can generally predict what effect a ray of light, a current of elec- tricity, the attraction of gravity or a change of temperature will have upon the behavior of the animal. Essentially the same statements may be made concerning the re-actions of our own heart, lungs and digestive organs, and there is no more reason for the assumption that the lower marine animals are conscious, than that these organs of ours are conscious. The instincts of most marine animals are inborn and are inherited from generation to generation, whereas in higher forins some of the instincts are acquired by personal experience, and are not present at birth or necessarily predestined to appear during life. Interesting studies of this subject are given by C. Lloyd Morgan in "Animal Intelligence," London, 1890; and by Jacques Loeb, in "Comparative Physiology of the Brain and Comparative Psychology," 1902. It has been proved that each and every animal and plant be- gins life as a single cell, and that the body of the individual is built up as a result of the division ajid consequent multiplication of this cell. Indeed, in one great group, the Protozoa the entire animal consists of but a single cell, which performs all of the life- INTRODUCTION 21 functions. In higher forms, however, the body is composed of an organized system of cells wherein we see a division of labor, some of the cells being digestive, others muscular, others serving to con- duct nervous impulses, etc. In the great majority of marine animals the eggs or young larvfe are cast out into the water, and it is interesting to ob- serve that even such sedentary forms as clams, oysters, starfishes, sea anemones, corals, etc., are nearly all free-swimming in their early life. It has long been known to naturalists that, in their develop- ment, animals pass through stages which recall the adult states of their more simply organized ancestors of the remote past, and Avhen it was discovered that the vast majority of marine larva? are free- swimming, it seemed probable that the most ancient marine ani- mals were so, and that the sedentary habits of life seen in sponges, corals, mollusks, etc., were of comparatively recent origin. We must not forget, however, that the free-swimming habits of the young are of immense advantage in leading to a wide distribution of animals, and that it may therefore have been maintained through the agency of natural selection at all times, or have been brought about as a result of adaptation. The stages passed through in the development of all animals are so complex, and yet show such a striking similarity of plan that there can be no doubt of the blood relationship of all forms one to another. As this is a most interesting and important matter, we will devote some space to its consideration. We will first speak of a typical case of development, such as is seen in the common starfish, and will then consider the more complex conditions exhibited in the worms, crustaceans and mollusks. The immature eggs of the starfish resemble a minute sphere, in the centre of which we find a small round body called the nucleus. When the egg is cast out into the water this nucleus divides into two nuclei, both exactly like the original nucleus. One of these new nuclei is, however, soon detached from the egg as a minute ball, and is thrown out into the water. The nucleus which still remains in the egg then divides into two half-nuclei, and one of 22- SEA-SHORE LIFE these is constricted olT and cast out, leaving the egg with only a half-nucleus. The egg is then mature and ready to be fertilized. This is accomplished by a single male germ cell, called a spermatozoon, myriads of which are cast out into the water by the male starfishes at the same time that the females are setting free their eggs. Each spermatozoon is an exceedingly minute cell with a globular front end, and along lash-like extremity, the movements of which drive it rapidly through the water. The globular front end of a single spermatozoon penetrates the egg and fuses with the half-nucleus; and it is most interesting to observe that this front end of the spermatozoon is itself a half- nucleus, in appearance similar to the half-nucleus of the egg. In this manner then is tlie final nucleus of the egg made up of two half-nnclei, one of Avhich is introduced by the male, while the other is maternal and belongs to the egg itself. After fertilization a Avonderful process sets in. This is called cleavage or cell division. First of all the nucleus divides into two similar nuclei, and these separate while at the same time the egg becomes cut into two, so that each half contains a nucleus. The halves of the egg do not, however, remain far apart but apply them- selves closely one to another, so that soon only a shallow furrow marks the position of the cleft which cut them in two. After a few minutes of rest the egg suddenly divides again, each half being cut into two, and this process is repeated again, and again, untd we have a great number of little cells all gathered together into a ball hardly larger than the original egg. Soon, however, we see that the ball is not a solid mass of cells, for the centre becomes hollow and filled with fluid, while the cells range themselves round the central cavity in a single layer. The creature thus becomes a hollow ball, the wall of the ball being composed of a single layer of cells. It is then that we first observe any active movement on the part of the embryo, for the outer sur- faces of the cells become covered with minute hair-shaped lashes the rapid movements of which cause it to spin through the water. This little, hollow, ball-like embryo is called a hlastula. Soon an interesting change takes place, for a part of the wall becomes pressed inward as one might squeeze in the side of a hollow ruli- Iger ball. This process is called "invagination," INTRODUCTION 23 The little embryo then has an inside layer of cells as well as an outside layer, and is called a gastrula. The cells of the pressed-in part are destined to give rise to the stomach, intestine and diges- tive glands. On the other hand the onter surface of the embryo gives rise to the skin and nervous S3'stein. All animals from the sponges up to man pass through a gas- trnla stage in which the body consists only of an outer and an inner layer. In many cases, however, as in worms, crustaceans, insects, mollusks, amphibia, reptiles and birds, the egg contains more or less 3'olk to provide nutriment for the developing embryo, and this introduces modifications of the process of cleavage, and formation of the gastrula so that it has taken long and careful study to discover that all embryos are at one time in the gastrula stage. Indeed, Huxley discovered that the jellyfishes were practically gas- trulce even when adult, for they have only a digestive cavity and an outer skin. In all forms above the jellyfishes, howev^er, we find a system of cells which come to lie between the digestive sac and the outer skin, and wliich gives rise to the muscles, and in higher forms to the skeleton. Although it will be impossible to do more than to present this crude sketch of the general processes of embryology, one will find a most fascinating field for thought in the study of such admirable works as "The Cell in Development and Inher- itance," by Edmund B. Wilson, or the " Text-Book of the Embry- ology of Invertebrates," by Korschelt and Heider, Macmillan Co. A most readable and yet condensed discussion of general em- bryology is given by Richard Hertwig in "Manual of Zoology," 1902, translated by J. S. Kingsley, p. 139-164. A list of a few of the more general and popular Avorks upon our marine animals may be of aid to those who desire to seriously study the subject For beginners who are engaged in collecting marine animals, and who desire to learn of their relationships, habits, structure and names, we Avould suggest : E. C. and A. Agassiz : Seaside Studies in Natural History, Tick- nor and Fields, 1805. 155 pages; 186 illustrations. A clear, popular, account of the structure and habits of our jellyfishes, sea anemones and star fishes and sea-urchins. C, B. and G. C. Davenport : Introduction to Zoology, Macmil- 24 SEA-SHORE LIFE Ian Company, 19(X). 412 pages; 306 illustrations, many of them being photographs from life. Most readable accounts of the rela- tionships of various forms, and also of their habits and anatomy. A. F. Arnold : The Sea-Beach at Ebb-Tide; Century Company, 1901. 490 pages; 85 plates and numerous figures, most of which are taken from previous publications. A good description of each species, and interesting chapters upon the relationships of each great group of the invertebrates. A. E. Verrill and S. I. Smith : Report upon the Invertebrate Animals of Vineyard Sound and Adjacent Waters. Report of the U. S. Fish Commission, 1871-2, 478 pages, 38 plates, 287 figures. Excellent accounts of habits and distribution, together with clear outline drawings of some of the animals. G. B. Goode, etc.: The Fisheries and Fishery Industries of the United States. U. S. Fish Commission, 1884. Two vols., 895 pages, 277 plates. Valuable to fishermen and collectors. Good general textbooks upon zoology, eml^ryology and anat- omy for those who have had the benefit of an elementary course in zoology : Richard Hertwig: A Manual of Zoology ; Henry Holt & Co. 1902. Translated by J. S. Kingsley. Korschelt and Heider, Textbook of Embryology of Invertebrates, Macmillan Company, 4 volumes, 1895-1900. Arnold Lang: Textbook of Comparative Anatomy, Macmillan, 1891-'96, 2 volumes. Every student of zoology should read Darwin's "Origin of Species." This work is to the natural sciences what Newton's "Prin- cipia " is to the physical and mathematical sciences. But it is more than an epoch making work, throwing a flood of brilliant liglit upon the dark mysteries of life. Its greatest inspiration to us comes because it is the record of one, who, after years of studious labor, performed under conditions of extreme distress which only love of truth could conquer, came into a realm of thought wherein he saw darkly and imperfectly, what we were, what our race had been, and what our possibilities. His characteristics were simplicity, honesty, and courageous thoroughness; fearlessly follow^ing the lead of truth far toward the limit of human understanding. SPONGES OR PORIFERA SPONGES are animals. The ordinary bath sponge is only the horny skeleton which in life was encased by living cells. In every living sponge, water is drawn in through numerous small open- ings, and thrown out through large ones. This water passes through the intricate channels of the sponge which are lined with thousands of minute cells, each provided with a collar, and a thread-like lash, which serves to capture and engulf the minute animals and plants that are drawn in with the water. In some sponges the skeleton is calcareous, and is composed of a vast number of curiously shaped spicules. In others it is mainly horny and fibrous as in commercial sponges, while in some, such as the Venus basket of the China Sea, it is glassy. The eggs develop within the sponge itself and are usually cast out as minute spherical or oblong larvte covered with cilia which enable the little creatures to swim rapidly through the water. In a few hours or days, however, they settle to the bot- tom and soon grow into sponges. Sponges of the same species often vary greatly in form, in accordance with the situation in which they grow, and they possess so little individuality that two sponges growing side by side will often fuse into one large mass. Sponges may also be cut into pieces, and each piece Avill grow into a perfect sponge. Good accounts of our American sponges are given by Hyatt, Memoirs of the Boston Society of Natural History, 1875 and 1877, and Lambe, Transactions of the Royal Society of Canada, 1892-94, 1896, 1900. COMMERCIAL SPONGES Our commercial sponges are found living only in the warmer seas, such as the waters of Florida, the West Indies, the Red Sea and Mediterranean. The sponges from Florida and the West Indies are inferior to those of the old world. There are many va- rieties of the commercial sponge but they all belong to the genus Spoitgia and have a skeleton made up of tough, closely meshed, horny 26 SEA-SHORE LIFE Fig I ; LIVING COMISIEECIAL SPONGE (Glove Sponge) The Bahama Islands. libres. The Qesliy parts which cover the skeleton are dark brown or black, and as the living sponge is usually more or less covered with mild or silt it is far from attractive in appearance, or pleasant in odor. There are ahvays a great number of little pores on the sides of the sponge, and water is drawn through these by means of the constant lashing of vast numbers of cilia which are borne upon the cells lining the passages. This water is forced out through one or m(n-e larger openings at the top of the sponge. In this manner the sponge tissues are aerated and the sponge captures the minute organisms upon which it feeds. Commercial sponges do not grow at depths greater than 200 feet, and the vast majority are obtained in water less than thirty feet deep, the best varie- ties being found at the greatest depth. The water is so Avon- derfully clear in the re- gions where they grow, that the fishermen mere- ly use a bucket having a pane of glass in the bot- tom through which they look in scanning the bot- tom for sponges. The sponge is drawn up by a pair of hooks fastened to the end of a Avooden pole. It is allowed to die, and is buried in dry sand until it is Fig. 2; THE HORNV SKELETON OF THE COMMEKCIAL SPONGE (Glove Sponge) from the Bahama Islands. SPONGES OR PORIFERA 27 Fig. 3; RED SPONGE, Long Island Sound. much decomposed, and then it is washed in the water to remove all of the fleshy parts, leaving only the tough, horny sl^eleton, which may be bleached in weak hydrochloric acid and hyposulphite of soda. Sponges grow best on hard bottoms where there is a consider- able current to bring food, and to pro- vide them with an abundance of aerated water. In Florida there are fiv^e varie- ties of sponges called " sheepswool," "yellow," "grass," "velvet" and "glove sponges." The Sheepswool Sponges, (Spongia equina gossypina,), are most valuable, the fishery being worth about S 250,000 annually. The fibrous skeleton is very tough and fine meshed, and the inter- ior of the sponge is cavernous while the outer surface is covered with woolly looking tufts of fibres. This is the common large bath sponge. The Yellow Sponge, (Spongia agari- cinaj, lacks the woolly tufts characteris- tic of the sheepswool, and its surface is apt to be fairly even, with numerous pit-like pores. The fishery is woi'th about $15,- 000 annually. The Grass Sponge, (Spongia grami- neaj, has the shape of a truncated cone the broad end being uppermost. The up- per surface contains all of the large open- ings and is usually depressed, giving the sponge a cup-shape. The sides are furrowed with numerous small openings between the ridges. The fishery is worth about $20,000 annually. In the Velvet Sponge, (Spongia equina ineandriformis,), the surface is apt to show winding channels bordered by flat ridges of fibre. The least valuable is the Glove Sponge (Spongia officinalis tuhidifera, Figs. 1, 2), in which the surface is quite even with dense fibres which project outward in fine tufts. The sponge is lasually Fig. 4; RED SPONGE, Long Island Sound. 28 SEA-SHORE LIFE .•-si... i,.>»> -,, Fig. 5/ Clam Shell infested with Boring Sponge, Long Island Sound. dome-shaped, not more than eight inches in diameter, and the fibres b'ecome brittle with age. S^Donges are reproduced from eggs which develop into free swimming larvEe, but soon settle down upon the bottom and grow into tlie sponge form. They will also grow very read- ily from cuttings or spores, and almost any fragment of a sponge is capable under favor- able conditions of regenerating a perfect sponge. A well illustrated paper giving an account of the com- mercial sponges of Florida is given by Dr. H. M. Smith in Bulletin of the United States Fish Commission, Vol. XVIT, 1897, p. 225-240. Among non-commercial sponges, the Red Sponge, (Microciona prolifera, Figs. S, 4), is foimd in shallow water from South Carolina to Cape Cod, and is very abundant upon oyster and scallop shells in Long Island Sound. It can be at once recognized by its brilliant crimson color. When young it forms broad, thin incrustations, but later it gives rise to branches which may be four inches in height. The Boring Sponge, (Clioiia sulplinrea, Fig. 5), a sulphur-col- ored sponge, is very destructive to the shells of oysters, clams, etc. It completely honeycombs and dissolves the shell, riddling it with galleries and holes, and finally growing over the outside. It is abundant along the sIku^cs from South Carolina to Cape Cod. Fig. 6; THE FINGER SPONGE, Salem Harbor, Massachusetts. SPONGES OR PORIFERA 29 The Finger Sponge, (Clialina oeulata, Fig. 6), is dull red or yellow in color and grows upon rocks or shells, forming finger- shai^ed masses about six inches high. At intervals there are large openings on the sides of the sponge which serve to allow the escape of water from the interior. This sponge is common north of Cape Cod at depths greater than fifteen feet. The Sulphur Sponge, (Suherites compaetaj, is a compact, heavy sponge which grows on sandy bottoms o\Y the Long Island coast. When living it is bright yellow, but soon darkens into an ugly brown after death. The surface of the sponge is smooth, rounded and nodular. The Urn Sponge, ( Grant ia ciliata, Fig. 7 ), is common in tide pools on Long Island where it grows in clusters of little urn-shaped sponges, each urn being dull yellow, gray or dral) in color, about one-half of an inch high, and with a large opening edged with spicules at the summit. It is found along our coast northward to Greenland, and is abundant on the northern coasts of Europe, being drawn in through sieve-like oj^enings on the sides of the sponge and forced out through the large terminal opening. Fig. 7/ URN SPONGE, Woods Holl, Mass. Water is constantly JELLYFISHES AND HYDROIDS >'i- \ JELLYFISH is an umbrella-shaped creature with tentacles -^^^ and sense organs arranged at intervals around the outer edge of the umbrella, while the mouth and stomach occupy the position of the umbrella handle. This description applies Avell to the large jelly fishes called Scyp]io))iednsce, but the smaller kinds called liydroniedusce have a deli- cate membrane extending inward all around from the umbrella-edge forming a diaphragm which partially closes the opening of the umbrella. Jellyfishes swim by rythmatically opening and closing their umbrella- like bodies. Jellyfishes are carni- vorous, feeding upon small fishes, Crustacea, or one an- other. They capture their prey by means of their ten- tacles which are armed {^f I with thousands of little ' < ^ '^ cells each containing a S ) minute coiled tube so slen- ( '" der that it appears to be '') a mere thread. When ex- cited these cells burst, and F,-^. 8; PORTUGUESE MAN-OF-WAR. ^j^g j-^^jg threads are shot out with such force that they penetrate the skin of the victim, carry- ing with them a poison which quickly paralyzes a small fish. The JELLYFISHES AND HYDROIDS 31 victim is then held in the stomach of the jellyfish for a few hours or days and the undigested remnant is ejected through the mouth. In common with other low invertebrates, the rate at which jelly fishes grow is dependent upon their supply of food. Indeed one can ob- serve them enlarge after every meal, and when starved tliey con- tract in size. The great majority of the jelly fishes are so small as to escape ordinary observation, but are on the other hand so numerous as often to cause a brilliant phosphorescence of the sea at night. The eggs of jellyfishes do not usually develop directly into new jellyfishes. In the large jellyfishes fScyplwmedusceJ the egg develops into a little pear-shaped creature whose body is covered with vibrating cilia which enable it to swim rapidly. Soon it set- tles down, and the narrow end adheres to the bottom. Then a mouth and a row of tentacles appear at the upper end. The little creature then grows for some months until suddenly it begins to constrict at intervals, and finally to split up into a series of thin, flat disks, each one of which swims off and grows into a separate jellyfish. In the smaller jellyfishes (Hydnwicdnscc) the egg changes into a beautiful little tree-shaped animal called a hydroid, and this gives rise to many little jellyfishes which bud out from it in various ways. Some jellyfishes, however, do not give rise to hydroids and many hydroids do not develop jellyfishes. Descriptions of the jellyfishes of our Atlantic coast will be found in "North American Acalephre," A. Agassiz, 1865; "Contri- butions to the Natural History of the United States," Vol. Ill, 1860, by Louis Agassiz ; C. W. Hargitt in "The American Naturalist," 1901, Vol. XXXV ; " Das System der Medusen," by Haeckel ; 3 vols., 1879-80, and "Medusa from The Tortugas, Florida," in the Bul- letin of the Museum of Comparative Zoology at Harvard, Vol. XXXVII, 1900 by A. G. Mayer. The Portuguese Man-of-War, /P/«/ysaZm nrethusa, Fig. 8). This beautiful animal is sometimes seen floating along our coast late in summer, but its home is in the tropical Atlantic and the Gulf Stream. The large pear-shaped float is filled Avith atmospheric air, and beau- tiful iridescent blues and pinks play over its surface and along its comb-like crest. Attached to the float there is a complex colony of 32 SEA-SHORE LIFE tentacles, finger-shaped feeding mouths, and grape-like clusters of reproductive organs. The tentacles are arranged in clusters, some being long and others short. When the wind blows, the long tentacles stretch out fully fifty feet, thus forming a drag to prevent a too rapid drifting of the colony. These tentacles are flat and ribbon- like and along one edge we see a purple line of bead-like stinging organs, which serve in the capture of fishes upon which the Physalia feeds. They inflict a most painful sting, and almost instantly par- alyze small fishes. When a fish comes in contact with the tentacles they immediately adhere to it, and the struggles of the fish cause the tentacles to contract, thus bringing the prey within reach of the numerous mouths which soon fasten upon it. If the fish does not struggle the tentacles soon cease to contract, and thus the mouths may be unable to seize upon their food. Despite its formidable weapons, however, the Physdlia is greedily devoured by Loggerhead turtles, but the turtle always closes its eyes when it seizes the prey. When very young the Physalia may sink for a time beneath the surface upon discharging the gas from its float; but in later life it loses this ability and remains constantly floating over the ocean at the mercy of the winds and currents. Only male Portuguese men-of-war are known, the female never having been observed. Velella iitutica, is an exquisite creature rarely seen along our coast, but it occurs in great swarms in the tropical Atlantic. The body is an oblong disk about four inches long, and deep blue-green in color. The upper side of the disk is occupied by the chambered , gas-filled float which is chitinous, and gives rise to a sail-like crest. On the under side of the disk we find a large central feeding-mouth surrounded on all sides by numerous little mouths and reproduc- tive polypites. Near the outer edge of the under side of the disk there is a row of long blue tentacles. Large numbers of little jelly- fishes are constantly budding off from the sides of the reproductive polypites and swimming away in the water; but their further de- velopment is unknown. Porpita linnmana, is related to Velella but is smaller, being only about one inch in diameter. Also the disk is flat and circular, and there is no sail-like ridge to the float. When seen in the water it appears as a deep blue circle, while the chambered float at the cen- tre glistens with a beautiful greenish iridescence. Underneath we JELLYFISHES AND HYDROIDS 33 Fig. 9. MILKY-DISK JELLYFISH, Vineyard Sound. find feeding polypites, reproductive polypites and tentacles very much as in Velella. Poi'iyita is rare along our coast, but between Cuba and South Carolina it is sometimes so abundant as to fleck the ocean for miles with specks of brilliant blue. The Sea-Blidaber, (Cija- nea arctica), is the largest known jellyfish. In the cold waters north of Cape Cod it grows to huge proportions, and one was found by Dr. Alexander Agassi z which measured seven and one-half feet across the disk and whose tentacles were fully one hundred and twenty feet long. On the Long Island coast, however, it grows to a much smaller size and thrives only in spring and early summer, disappearing about the middle of June. Large as these creatures are, however, when dried in the sun it is found that the animal substance is only y|o part of the whole ; the vast bidk of the creature's body being composed of sea water. The disk is amber-colored with a rosin-colored centre marking the stomach-space. There are sixteen notches at regular intervals around the edge of the disk, and eight of these notches are occupied by sense organs which contain granular concretions. On the lower surface of the disk one finds the central mouth surrounded by veil-like lips, and eight clusters of tentacles. The eggs are caught in the veil-like folds of the lips and set free as little pear-shaped larva which swim rapidly through the water by means of their cilia. Soon, however, each larva settles down upon the bottom and develops into a polyp having a terminal mouth surrounded by tentacles. After feeding and growing for some months the polyp begins to display constrictions at regular inter- vals, and soon it splits up into a series of disks, each one of which is set free and becomes a jellyfish. 34 SEA-SHORE LIFE The Milky Disk, (Aurelia flavidula, Fig. 9J, is common north of Cape Cod to the Arctic Ocean, but is not very abundant along our coast. The disk is about one foot in diameter, is flatter than a hemisphere and is slightly milky in color, while the four horse- shoe-shaped reproductive organs near the centre are yellowish-white or pink. The mouth is at the centre of the concave side of the disk and is surrounded by four long frilled lips. Sixteen sti'aight and sixteen pitchfork-shaped vessels extend outward from the central stomach to the edge of the disk. The little pear-shaped lar- vae are cast out in im- mense numbers, and ( >. ^^^- ^'^^ after swimming about i- ^ ^\ vv^-C^N ^°^' ^ ^^""^ '^''lys, they set- ^ .'^ \ \ "\~\^ \ . ■ tie upon the bottom and develop a ring of tentacles in a zone around the mouth. Finally the body of the larva splits up into a series of disks, each one of which swims off and develops into a full-grown jellyfish. The Speckled Jel- lyfisli, fDactylometra qiiinquecirra, Fig. 10 J, is found in a few local- ities, as at Tiverton, Rhode Island, in great abundance, during the latter half of the sum mer, and it occurs in the upper reaches of many other Ijays and estuaries from Florida to Cape Cod. The disk becomes about one and one-half feet in diameter, and its margin bears thirty-two notches and, when fully grown, Fig. 10 ; SPECKLED JELLYFISH. JELLYFISHES AND HYDROIDS 35 forty tentacles. The veil-like lips around the moutli form long, graceful curtains often two and one-half feet in length. This me- dusa can be at once distinguished by its amber-pink coloration, and the sixteen spoke-like areas of reddish specks upon the convex side of the disk. There are eight sense organs, each containing a spherical mass of concretions. These are situated at regular inter- vals within notches at the disk-margin. The Milky Cross, (Staurophora laciniataj, is abundant along the Atlantic coast north of Cape Cod, during the summer months, and is occasionally seen along our coast in spring The appear- ance of a milky-colored cross is produced by the large cruciform mouth bordered with veil-like frills containing the reproductive organs. It is from four to eight inches in diameter. There are numerous little eye spots at the base of the tentacles, upon the bell margin. The Thimble-Jelly, (Melicertum campanula J. This little Arctic jellyfish resembles a large thimble of clear jelly-like substance with eight, yellow, radial canals extending from the stomach at the centre of the concave side of the thimble to the edges forming, so to speak, the spokes of a wheel. The edge of the bell is provided with numerous tentacles. It is exceedingly abundant until mid- summer, north of Cape Cod, but is found on our coast only in the spring. ( Gonionemus murhachii, Fig. 11). This interesting little jellyfish is famil- iar to all who study at the Woods Iloll Laboratory, for it is very abundant in the Eel Pond at that place. The bell is transparent, somewhat flatter than a hemisphere, and when full grown it becomes about one inch in diameter. About eighty long, flexible tenta- cles arise from the side of the bell near ^^- ''^ f "yj!*^- fZ'7T" tnurbac/ni, Woods Holl, Mass. the rim. Each of these bears a sucker- like disk upon its upper side near its extremity, and the extreme tip of the tentacle bends sharply at right angles. The tentacles are cov- ered with wart-like clusters of minute thread-cells each containing a coiled tube which can be turned inside out as we might do with the 36 SEA-SHORE LIFE finger of a glove. If the tentacles come in contact with a small fish or crustacean these little stinging- threads are instantly dis- charged, and on account of their minute size they penetrate the skin of the prey carrying with them a poison, believed to he formic acid, which quickly paralyzes the victim. Scattered between the tentacles there are numerous little balancing organs, which may also serve to detect vibrations in the water. These organs consist of minute capsules each con- taining a hard spher- ical concretion. The stomach of the me- dusa is a four-sided tube at the centre of the concavity of the bell. Four canals ra- diate outward from this stomach and ex- tend 90° apart, to a vessel which encir- cles the bell margin at the bases of the tentacles. The geni- tal organs are devel- oped upon these I'a- dial canals. They are ribbon-like, but each ribbon is longer than the portion of the canal upon which it is developed, and its edge is therefore folded sinuously from side to side. The stomach, genital organs and tentacles are rich brown in color with green spots, while the other parts of the jellyfish are transparent and gelatinous. According to Perkins, the jellyfish is very active upon cloudy days, when it swims rapidly upward to the surface, opening and closing its umbrella-like bell with powerful pulsations. Upon fig. 12; PASSION-FLOWER HYDROID (From Life). Aniiis(iuam, Mass. JELLYFISHES AND HYDROIDS reaching the surface, however, it becomes suddenly quiet and then slowly sinks down with tentacles widely distended. Frequently it clings to seaweed and other objects by means of the suckers upon its tentacles. This jellyfish lays its eggs during the summer at about one hour after sun-set. The little larvae are pear-shaped and swim with the blunt end forward. Soon they settle with the blunt end down- ward and four tentacles soon develop at the narrow end, surround- ing the mouth. Other little pear-shaped larvae often l)ud out from the sides of the original one, are set free, and after swimming about for a time settle down as did their parents. It is probable that the larva finally changes directly into a little jellyfish. This medusa was first discovered in the Eel Pond at Woods Roll, by Louis Murbach, 1895. Yerkes and Aver, in "American Journal of Physiology," Vol. IX, 1903, have made a careful study of the reactions of the medusa to light. The Passion-Flower Hydroid, fTliaiiniocnidia spectabilis. Fig. 12), often grows upon sunken ropes, or within shaded tide-pools. It consists in a dense cluster of delicate am- j ber-gray stems, each terminating in an en- \i /; larged, pink -colored polyp-mouth sur- rounded by two rows of tentacles. The stems are each about three inches long, and the beautiful flower-like heads give the creature the superficial appear- ance of a plant; but it is an animal, and the tentacles serve to cap- ture its prey of small Crustacea and etc., which it stings to death by its tliread-cells. The Eel-Grass Hydroid, (PenmD-ia tiarella. Fig. 13 ), grows abundantly upon eel grass or in tide-pools. It is from three to six ^i^. is; EEL-GRASS HYDROID, Long Island Sound. 38 SEA-SHORE LIFE inches liigli, and resembles a little dark-colored tree with branches arranged alternately on either side of the main stem. Each branch gives rise to a series of side branches on its npper side and they each and all terminate in white or pink flower-like heads. These polyp-heads bear the mouths, and each is surrounded by two rows of tentacles which wave through the water intent upon the capture of the small marine animals upon which the Pennaria feeds. Jelly- fishes grow out from the sides of the polyp-heads, and within these the eggs develop At times the eggs are cast out before the jelly- fishes are set free, but often the jellyfish escapes from the hydroid and swims aboiit, car- rying its eggs with it. The eggs then develop into little pear-shaped larvae Avhich swim rapidly through the water but soon settle down and change into tree-like hydroids which in turn develop another genera- tion of jelly fishes. In spring and early sum- mer large, pale colored, stocks of Pennaria are found upon rock weed, piles, etc.; but about the middle of August small, highly colored stocks, with pink heads, are found in great abund- ance upon eel grass. This was observed by Professor Hargitt in "The American Naturalist," Vol. XXXIV, p. 390. The Sea Plume, (Ohelia cum- iitissuralis, Fig. 14), is common upon the wooden posts of wharves or attached to stones or sea-weed. The main stems are fully six inches long, and they give rise to spirally arranged branches which run nearly at right angles to the stem. The creature thus resem- Fig. 14; SEA-PLUarE (Obeha), Growing Upon Seaweed (Fucus). From Life. JELLYFISHES AND HYDROIDS 39 bles a delicate seaweed or plume, but is in reality an animal. Each branch gives rise to a number of little flower-like polyp-mouths surrounded by tentacles which capture prey. Jellyfishes develop within capsules at the angles of the stems. These jellyfishes are set free and swim about for a long time, finally growing to be about one-quarter of an inch in diameter. Then they cast out their eggs which develop into plume-like hy- droids which in turn give rise to jellyfishes. The Rainbow Jelly, fMnemiopsis leidyij, is one of the comb- jellies or CtejiophorcB. It is exceedingly abundant along our coast during the summer, but is so transparent that it would escape observation were it not for the brilliant flashes of prismatic red and green that play over its eight rows of comb-like flappers. When full grown the creature is about four inches long, and the outline of the body is pear-shaped with broad wings on the sides. At the narrow end there is a sense organ consisting of a capsule filled with a ball-like mass of concretions. This sense organ enables the creature to maintain its proper position in the water. The central stomach gives rise to a complex system of ramifying tubes which extend through the Avings and along under the eight rows of combs. This creature is so delicately formed that it can not be lifted from the water without serious injury, yet it readily captures small fish and crustacea upon which it feeds. At night it gives out a brilliant green phosphorescence when disturbed. One often finds a long, pink, worm-like parasite imbedded within the gelatinous substance of the Rainbow Jelly. This is not a worm, however, but is a sea anemone, Edwanlsia leidiji. SEA ANEMONES AND CORALS 4 SEA ANEMONE is a barrel-shaped animal. The bottom of ^^ the barrel is fastened to some rock or other firm anchorage, while the upper end bears a slit-like mouth which is encircled by a fringe of tentacles. The mouth leads into a simple tube-like throat, which is bound to the inner sides of the barrel by means of radiating partitions. The throat-tube is, however, only about one-half as long as the height of the barrel, so that the radial partitions in the lower half Fig. is; EYED-CORAL, From Life. Nassau, Haliamas. Orbicella acropora. of the barrel cavity do not meet at the centre, but leave an open space which is the "stomach" of the anemone. Sea anemones are among the most attractive of marine animals, beautiful both in SEA ANEMONES AND CORALS 41 form and color. They vary in size from that of a pin's head to several feet across, and they live at all depths and in a great variety of situations. A. coral polyp is only a sea anemone which deposits a plate of lime salts at the base of its barrel-like body and between the Fig. i6; Star-Coral Showiug Liviug Polyps. From a Specimen in the Xew York Aquarium. radial partitions of the stomach cavity. These lime salts form a stony "skeleton" or substance which we commonly call "coral." It is well to remember that the coral animals are not "insects" but are merely sea anemones which form stony 'skeletons." Although sea anemones and coral polyps resemble beautiful flowers when fully expanded, they quickly contract into a mere dome-shaped mass when disturbed. In this way the coral polyps are protected by withdrawing into their stony cup-shaped bases. 42 SEA-SHORE LIFE Sea anemones are found in all oceans, but the stony corals are practically confined to tropical and sub-tropical regions and will not usually live in water which is colder than C)fi° F. In the trop- ical Atlantic and Pacific thousands of coral islands called atolls have been gradually built up by the con- "-•»•: ■ iT*** •• '.'■•'''. ■i.'.^Q ■y:r-fw -^^ % ■^^ Fig. jj; Stony Skeleton of Star-Coral. Long ; Island Sound. stant growth of coral polyps, and every grain of sand on the Baha- mas, Bermudas, or Florida Keys was once part of the skeleton of a coral polyp or belonged to some animal or plant which lived among the coral reefs. The Star-Coral, (Astrangia dance, Figs. 16, 17 J. This stony coral extends farther into the tem- perate zone than any other species, being found from the Carolinas to Cape Cod. It is abundant in Long Island Sound where it forms encrusting masses of star-like cups upon stones, dead shells, etc. The coral polyps are glassy white, and translucent, and have each from eighteen to twenty-four long, tapering ten- tacles Avhich end in a Avliite knob and are speckled over with white warts. These are the stinging organs which en- able the coral to capture its prey of small marine animals. When fully expanded the pol- yps are about one-eighth of an inch wide and three-eighths high, but when disturbed they suddenly contract so as to become practically invisible. The colony starts with a single polyp but soon others bud out from its base, Ftg. iS ; FLESHY CORAL. Woods Holl, Mass. SEA ANEMONES AND CORALS 43 and the cluster increases by further budding from the bases of the older polyps until it may be several inches in diameter. The Fleshy Coral, ( Aleyoneum carneum, Fig. 18 J, is found from the eastern end of Long Island to the Gulf of St. Lawrence. It is Ftg. 19; BROWN SEA-ANEMONE. Expanded. From Life. rarely seen in shallow water but is common upon rocks at depths greater than 2() feet. When first brought up from the bottom it appears as an ugly, tough gelatinous mass covered witli dull yellowish-pink finger-shaped processes. If placed in water, how- ever, the whole mass soon appears studded with beautiful star- shaped polyps, which expand so as to give the appearance of a stump covered with delicate pink flowers. Each of these polyps has a terminal mouth surrounded by eight tentacles, the sides of which are bordered with rays giving a feathery appearance. The whole colony of polyps develops through constant budding from the sides and bases of the older parts of the colony. Alcyonaria or fleshy corals are extremely abundant in the tropical Pacific where they often cover the reefs for acres in extent with a tough, leathery -looking carpet studded with eight-rayed 44 SEA-SHORE LIFE polyps. Others form liemisplierical heads hearing beautiful star- like polyps each having eight feathery tentacles, while still others form the sea whips and sea fans so characteristic of an Atlantic reef. In the sea fans, however, the polyps secrete a horny axis which forms the internal framework of the fan and gives a tough support for the fleshy parts which cover its surface. Nothing is more strangely beautiful than these coral reefs where the rich pur- ple sea fans and the chocolate sea whips wave gracefully to the surges in the crystal depths, while brilliant fishes glistening in green, blue, purple and yellow, glide in and out among the shad- ows of the coral caverns. The precious coral of the Mediterranean is allied to the sea whips. Its polyps are brilliant white, and have each eight feathered tentacles ; while the internal axis of the colony is red and stony. The Brown Sea Anemone, (Metridium inargination, Figs. 19, 20), is our common sea anemone, which extends from New Jersey to Labrador. It is abundant in tide pools, and upon the posts and rock work of wharves in Long Island Sound, but it attains a much larger size and more brilliant color north of Cape Cod. Fig. 20. 15ROWN SEA-ANEMONE, Contiacted. Sliowiag the white thieatl-like tihimeiibs called acontia which are extruded as a means of defense. Although usually brown in Long Island Sound, individuals of a pure white, delicate salmon-pink, or olive, are common at Newport SEA ANEMONES AND CORALS 45 and farther north. Large specimens are about three inches wide and four high. When expanded the body is cylindrical with a dense fringe of tapering tentacles surrounding the slit-like mouth. The tentacles are covered with minute hair-shaped organs, or cilia, which wave outward so as to create a current from the base toward the tip of the tentacle, and they are also armed with thread cells that sting the small creatures upon which the anemone feeds. These sea anemones develop from eggs, but they also slowly divide ; an originally single anemone sometimes splitting longitu- dinally until two are produced. In addition ilrs. M. L. Hammatt dis- covered that little anemones are often budded out from the base of large ones. The body of the anemone contains powerful muscles, and when the animal is disturbed these contract so that the tentacles are rolled inward and hidden away, while the body becomes a mere dome-like Fig. 21, ■ AVHITE-ARMED ANEMONE. Fiom Life. Specimens in tlie New York Aquarium. mass. Long, white, thread-like filaments are also extruded through pores in the sides of the body. These filaments (Fig. 20), are called acontia, and bear great numbers of stinging thread-cells. The White -Armed Anemone, ( Sagartia lencolena, Fig. 21 J, is common off the Long Island coast, and extends from the Carolinas to Cape Cod. It is slender, the body being somewdiat more than two inches long, while the tentacles are about one inch in length. 46 SEA-SHORE LIFE It lives in dark situations on the under sides of stones, or upon the shaded piles of wharv^es below low tide level. Sometimes, how- ever, it is found almost buried in gravel or coarse sand. The body Fig. 22; SAND-ANEMONE, Long Island Sound. is of a delicate amber-brown, and is semi-translucent while the long tapering tentacles are white or translucent-brown in color. This species thrives well within a salt water aquarium. The Passion-Flower Anemone, (Coudylactis yassiflora), is found in the West Indies and Bermudas, where it is abundant upon broken rocky bottoms. It attains a large size, often being more than a foot in diameter and six inches in height. It is a very beautiful anemone. The body is vermillion, while the tentacles are rich turquoise-green Avith purple tips. The Sand Anemone, f Halcampa producta, Fig. 22), is common from South Carolina to Cape Cod in sandy or muddy beaches, the elongate worm-like body being buried quite out of sight with only the tentacles exposed. It is three or four inches long and about one-half of an inch in diameter, but when disturbed it may contract so as to be not more than two iuches in length. There are about twenty short, blunt tentacles and twenty longitudinal rows of whitish warts along the SEA ANEMONES AND CORALS 47 sides of the body. The color is dull yellowish gray, and altogether it is not an attractive object. The Orange-streaked Anemone, ( SagaHia lucicej, is now the most abimdant species in rocky tide-pools of Long Island Sound. It appears to have been introduced upon oyster shells from the south, for previous to 1892 it was unknown along our coast. In that year it was found by iliss L. L. Verrill, near New Haven, and it has gradually spread northward, reaching Salem, ]\Iassa- chusetts, in 1901 ; beyond which place it appears not to exist. It is only about one-quarter of an inch wide and three-eightlis high, aad there are about forty-eight slender tapering tentacles. The body of the anemone is olive green or brown, usually with twelve fine longitudinal orange, or lemon yellow, streaks; while the tentacles are light brown, almost white. The best description of this anemone is that of Mrs. Gertrude C. Davenport in the "Mark Anniversary Volume," p. 137-14-4. She discovered that the anemone often splits into two, and the halves soon separate, and grow to their original size. Fragments may also be separated from the base, and then regenerate into new individuals. The Crimson Anemone, f Tealia crassicornis J , is of moderate size, being about two inches high and one and one-half in diame- ter. It has about 160 blunt tentacles, and the body is covered with tubercles. It is found in tide-pools, and upon rocky bottoms north of Cape Cod, and may be recognized by its rich cherry-red or crimson color, although some specimens are mottled with red and bluish-green. A drawing of this species is given in Agassiz's "Seaside Studies," p. 13, under the name of Bhodactinia davisii. The Parasitic Anemone, ( Edwardsia leidyij. Sea anemones live in almost every conceivable situation upon rocky shores, in muddy or sandy beaches, or upon shells which are being carried about by hermit crabs, while others float over the ocean, or swim freely about. Some are even parasitic, and among these Edwardsia leidiii is most remarkable. It lives Avithin the transparent Rain- bow Jelly (Mncmiopsis leidi/i. See page 39^*, and its long, dull pink, threadlike form caused it to be mistaken for a worm. It is about one and one-half inches long and only about one- sixteenth of an inch in diameter, and there are sixteen blunt 48 SEA-SHORE LIFE tentacles. Its nearest relatives are slender little sea anemones with eight lozigitudinal farrows on the body and sixteen tentacles. They live in rocky tide-pools. The Cake- Anemone, fStoicliactis lielianthus, Fig. 23 J, is com- mon in the West Indies and Bermudas, where it lives in shallow water under rocks or in crevices. It resembles a " pancake " from Fig. 23; CAKE-ANEMONE. Toitugas, Florida. three to five inches in diameter, the oval mouth being in the centre, and numerous short blunt tentacles covering the upper surface. This anemone adheres to rocks by means of its sucker-like base, but it can slowly move from place to place. It is usually olive- yellow, often mottled with green or olive-brown. STARFISHES SEA-URCHINS AND SEA-CUCUMBERS ^^TARFISHES, sea urchins, sea lilies and sea cucumbers are called Ecliinoderms. In the form of their bodies and ar- rangement of their organs they usually display five ra3^s, and are therefore known as "radiates." For example, most starfishes have five equally developed arms, 72° apart, recalling the rays of a conA-entional star. In the Ecliinoderms the skin usually contains a skeleton composed of calcareous plates of definite shapes, all hinged together in an orderly manner, so as to make a veritable armor which gives rigidity to the body, and protects the soft organs of the interior. In the living starfish one will see hundreds of little tubular feet which arise from the grooves on the lower side of the arms. When the starfish is tui-ned over upon its back these feet stretch out to a remarkable length and wave about, seeking to fasten upon something in order to right the animal. It is then we may see that each of these feet is a hollow tube ending in a cup-shaped sucker. Similar tube-feet will be seen in five double lines along the sides of the sea urchins. The mouth of the starfish is at the centre of the lower surface. On the upper side, and a little away from the centre between two arms, one will see a spongy-looking area. This is called the madreporic plate, and is the sieve-like entrance to the water-tubes of the starfish which extend down the arms and give rise to little Ijladder-like vessels one above each tube-foot. The contractions of these little bladders cause the tube-feet to elongate by pressing water out into their cavities. The upper surfaces of most of the starfishes are covered with spines, but these are much better develoj^ed in the sea urchins where, in addition to spines, we find calcareous pincers mounted ujDon rods, which are used to remove any injurious foreign sul)- stance that may fall upon the body of the urchin. The sea cucumbers, or Holothuria, are worm-like in appearance, but are nevertheless closely related to starfishes and sea urchins. 50 SEA-SHORE LIFE They have no spines and their skeleton is often reduced to minute anchor-shaped spicules within the skin. The mouth is at one end of the worm-shaped body, and is surrounded by feathered or branching tentacles. In some species there are five double rows Fig. 24; Variations of tlie COMMON STARFISH. From Long Island Sound. of tube-feet down the sides of the body, but in others these are absent. When disturbed sea cucumbers have the curious habit of casting out their viscera, and afterwards regenerating them. They are sluggish creatures, and either live within the sand or under rocks or crawl slowly over the bottom, feeding upon minute organ- isms that are contained in the sand or mud which they swallow. Sea urchins or Echini may be compared to starfishes Avithout arms. They are usually provided with a skeleton made for the most part of six-sided plates fused or rigidly joined together. They have five sharp-edged teeth with which they gnaw off minute STARFISHES, URCHINS AND SEA-CUCUMBERS 51 seaweeds from the rocks. Some species can even gnaw away the rock itself, and in many parts of the world we find that the sea urchins have literally honey-combed the rocks; indeed we often find a sea urchin living in a cavity whose opening is too small to allow of the animal's escape. The common sea urchin of Europe is sold in the markets during the season when it is full of eggs. The sea lilies or Crinoidea are now among the rarest and most graceful of inarine animals. It is probable that all other sorts of Echinoderms are descended from ancestors resembling the sea lilies, for in long past ages they were far more abundant than any other Echinoderms, and even in the age of the chalk they lived in countless numbers in shallow water along our shores, their flower- like bodies mounted upon long delicate stems that formed veritable forests beneath the sea. The sea lily is not a plant, however, but may be compared to a starfish mounted xipon a long stem which arises from the middle of its back and anchors it to the bottom of the sea. The mouth is turned upward, and is surrounded by branching arms which sweep gracefully to and fro in search of prey. The Echinoderms live only in salt water, but they are found at all depths and in all oceans, from the Tropics to the Poles. The vast majority crawl over the bottom, but at least one holothurian"'^ swims through the water, and was at first mistaken for a jellyfish. Most of them cast their eggs out into the water, and the larvse develop bands of waving cilia, which enable them to swim about for a considerable time. Suddenly the body of the Echinoderm begins to develop Avithin the larva, and most of the old larval body is absorbed or cast off. The Common Starfish, (Figs. 24, 25). There are two well marked varieties of the common starfish ; one called Asterias forhesii extends along the coast from the Gidf of Mexico to Massachusetts Bay but is rare north of Cape Cod. It is found from low tide level to a depth of 120 feet, and may be recognized by its somewhat blunt-tipped arms, to^^gh, spiny skin, and the bright orange madre- poric plate. In the North it is replaced by another form called Asterias vid- '^' Pelagoihu) la tiatat}ix, Jleuioirs Museum Comparative Zoology at Harvard, Vol. XVIf, No. 3, 1894, Plate XIX. 52 SEA-SHORE LIFE gm^is which is found from North Carolina to Labrador, bnt is com- mon only north of Cape Cod. In this starfish the arms are more pointed than in .4. forhesii, the skin is not so rigid, and the madre- poric plate is of the same color as back of the animal, which may be Fig . 25 ; Left : HORSESHOE CEAB. Ri^ht: COMMON STARFISH. Bel07i<: (JREEN SEA-URCHIN. purple, yellow, brown or beautiful shades of pink or red. It ranges from low tide level to a depth of 1200 feet. Many naturalists con- sider these two forms to be identical, but the writer found that in Asterias forhesii from Long Island Sound, 78 individuals in 10,000 had more or less than five arms, whereas in A. vulgaris from Mas- sachusetts Bay only 23 in 10,000 had more or less than five arms. It seems, therefore, that the southern form is more than three times as variable as the northern. There is a minute red eye-spot at the tip of each arm of the starfish. Hundreds of sucker-like tube-feet arise from a deep groove that extends down the mid ventral side of each arm, and between two of the arms on the upper side of the disk one may see a bright colored area called the madreporic plate. Its situation marks the sieve-like entrance to the water tubes of the starfish. STARFISHES, URCHINS AND SEA-CUCUMBERS 53 The mouth is at the centre of the lower side of the disk and is sur- rounded on all sides by the tube-feet. In summer and autumn the starfishes are found on rocky- places in shallow water, but in winter they live at greater depths. Starfishes feed upon almost any kind of mollusk, but will also devour barnacles, worms, and occasionally sea urchins or even the young of their own species. It is estimated that in 1888 starfishes destroyed $631,500 worth of oysters on the beds of Connecticut alone. Their mode of feeding is interesting. The starfish folds its arms over the clam or oyster, and hundreds of the sucker-like tube-feet fasten themselves to the valves of the shell, so that finally the mollusk yields to the constant pull of the starfish, and the shell gapes open. Then the starfish turns its stomach inside out and engulfs the mollusk. It has been found by expei'iment that a large starfish can exert a steady pull of over two and one-half pounds and that this is sufficient in time to open the valves of a clam or mussel. The eggs of the starfish are discharged into the water in great- est abundance during the last three weeks of June, although tliey are also to be found throughout the summer, and occasionally even in winter. These eggs soon develop into little transparent larva? cov- ered with tortuous lines of waving cilia, and provided with long flexible tubercles. They swim slowly about near the surface, and feed upon minute organisms until they grow to be about one-eighth of an inch long. Then the iipper and lower halves of the star be- gin to develop xipon both sides of the stomach, and in a few hours all of the anterior part of the larva and the tul)ercles are absorbed, and only a minute star, about as large as a pin's head, is seen upon the bottom of the ocean. Myriads of these little stars settle upon sea weeds and eel grass, and begin at once to devour the young clams which also begin life in the same places. Professor Mead found that one of these little stars devoured over 50 young clams in 6 days. The starfishes grow rapidly, and in one year they may have arms 2^ inches long and be ready to spawn. It is certain that the menhaden devour myriads of starfish larvte as they swim through the water. Normal starfishes have five arms, but occasionally one is found 54 SEA-SHORE LIFE having more or less than tliis number. Some of these variations are the result of accident, but others are congenital. Starfishes regenerate readily, and although a single detached arm will not regenerate a new star, it will do so if it be torn off to- .^^-EMfioii 's^m£::y^ Fig. 26; BLOOD-STAR. Massachusetts Bay, Tide Pools. gether with about one- fifth of the central disk. Also the central disk if deprived of all of the arms will soon regenerate them. When an arm is injured it is iisually cast off voluntarily very near to the central disk, and regeneration begins at this point. Regen- eration from the injured tip of an arm is very rare. By means of their hiuidreds of sucker feet starfishes are enabled to glide rapidly over the softest mud. They can also climb readily and if turned over will quickly right themselves. When the water is perfectly flat and calm they can even move sucker-side uppermost along the surface of the water. The Blood Starfish, fCribrella sanguinolenta, Fig. 26 J, is smaller than the common starfish, and its arms are rarely more than an inch long. It is pink or reddish and the arms are almost smooth, be- ing covered with numerous little warts. The leathery skin is quite soft and flexible, and the arms are rounded in cross sections, and taper to a point. The eggs are not cast out into the water, but are held around the mouth of the mother until they have developed into little star- fishes. This creature is abundant witliin rocky tide-pools from the eastern end of Long Island to the Arctic Ocean. STARFISHES, URCHINS AND SEA-CUCUMBERS 55 The Mud Starfish, fCtenodiscus crisiMtus, Fig. 27), is abund- ant upon muddy bottoms at depths greater than 100 feet from Cape Cod to the Arctic Ocean. The upper surface is covered with a flexible skin beset with niimerous regularly arranged granulations. The sides of the arms are straight and vertical, giving the starfish the appearance of a five-rayed cake cut out of a thick sheet of dough. At the centre of the upper surface of the disk there is a pro- jecting papilla. In this connection it is interesting to observe that starfishes are probably descended from forms which were attached to the bottom by means of a stalk that extended downward from the middle of the aboral side, and it is possible that the little blunt Fig. 27; ML'D-STAR. From a Deptli of 120 Feet Off Cape Ann, Mass. papilla seen in the mud star is the remnant of the base of such a stalk that has long since ceased to serve as an organ of attachment. The feet of this starfish have no terminal suckers, and serve merely to push the animal along as it glides over the mud. The arms are sharp-pointed although short and blunt, and the creature is about two and three-quarters of an inch in diamter. The starfish is dull ochre-yellow or slightly greenish in hue. It swallows large quantities of mud, and probably subsists upon minute organisms contained therein. The Giant Starfish, (Pentaceros reticulatus, Fig. 28 J, is found on sandy bottoms, usually at depths greater than ten feet, off the Florida coast and West Indies. It is the largest of our starfishes, 56 SEA-SHORE LIFE the disk being about five inches thick, and one and one-half feet in diameter. The five arms are short and blxmt, and the up- per surface is covered with short, blunt, rounded spines, Avith a network of ridges between them. The color is brown, or brownish-vellow. The Green Ser- pent Starfish, (Ophi- uva hrcvispinaj , is a West Indian and Tropical Atlan- tic species, but it is common in some parts of Long Isl- and Sound where the bottom is cov- ered with eel grass, as in Great Peconic Bay. It is dark, rich olive green in color, and the central disk is five-sided and about one-half of an inch Avide. The long, slender arms arise sharply from each of the five angles of the central disk. These arms are each about two and one-half inches long, and are covered with scales which give rise to short spines along the sides. In life they thrash about in a snake-Jike manner. The Serpent Stars are the most active of all starfishes, for their long, flexible arms and tube feet enable them to clamber rapidly over the ground. Although no eyes are known to exist they readily perceive the approach of an enemy, and will dart into the nearest rocky crevice with remarkable rapidity. If one of the arms be seized, it is immediately thrown off leaving the remaining parts of the Star to escape. The Brittle Starfish, fOphiopholis aculeata, Fig. 29 J, is readily distinguished by its mottled coloration in light gray and purplish brown, no two individuals being alike in pattern. The disk is M?. 28; GIANT STARFISH. From Sandy Bottom at Tortiigas, Florida. STARFISHES, URCHINS AND SEA-CUCUMBERS 57 granulated with, minute spines, and the arms are provided with rows of stout, blunt spines, usually six in a row There are ten egg-pouches on the lower side of the disk near the points of origin of the five arms. The starfish is rare in shallow water but is abundant at a depth of about 100 feet, where it crawls about among the rocky crevices. It extends from the coast of New Jersey to the Arctic Ocean, and is common on the northern coasts of Europe, and the Pacific coast of North America. It is figured by Lyman under the name Ophiopliolis hellis. The Basket Starfish, (Astrophy- ton cKjas^Hizii, yi is a species of serpent star whicli is inter- esting in that the arms branch in a forked manner. The central disk is five-sided, and the arms arise from the five angles. At each angle we see two main branches of the arms, then each of these forks giving four branches, and these soon fork again, giving eight. This process is repeated, until, according to Governor John Win- throp of Connecticut, who first described this creature in 1670, the arms give rise to 81920 terminal branches. The basket star walks ujDon the tips of these branches, with its body elevated above the ground, and a perfect trellis work of arms sloping outward, so that the creature is about one and one-half feet in diameter. It is dull yellow and brown in color, and is covered Fig. 2g; BRITTLE STARS. From Life. Tide Pools; Annisquain, Mass. 58 SEA-SHORE LIFE . ..iHs*ai«e«**«»-»- - Fig. 30; BASKET STARFISH. Tortugas, Florida. with a tough skin. The basket star feeds upon unlucky fishes which may seek a retreat within the branches of the trellis, only to be seized and devoured. It is found along our North Atlantic coast from the eastern end of Long Island north- ward, and although rare in shallow water, it is abundant at depths of twenty feet or more, being especially com- mon off Provincetown or in Eastport Harbor. The Purple Sea Ur- chin, (Arhaeia pune- tidata, Fig. ^iy), a dark brown or brownish-purple sea urchin, is quite common on broken rocky bottoms along our coast from Mexico to Cape Cod. The body is globular and hejnispherical, and about one and three-quar- ters inches in diameter. It is protected by a skeleton formed Avithin the skin, and composed for the most part of six-sided calcareous plates arranged in an orderly manner. The body is covered with conical spines of various lengths up to about three-quarters of an inch. These are found chiefly in five broad radii regularly spaced around the body, while between these spiny areas one sees five nar- row spaces almost devoid of spines. There are five double rows of tube feet provided with ter- minal suckers. These arise in the spiny areas and may stretch out so as to become longer than the spines themselves. At the Fig. ,,v/ PURPLE SEA URCHIN. Cold Spring Harbor, Long Island Sound. STARFISHES, URCHINS AND SEA-CUCUMBERS 59 centre of the under side is the mouth with its five white teeth pro- vided with powerful muscles Avhich enable them to grind the vege- table food upon which the sea urchin lives. Tlie mouth leads into a coiled intestine which opens by a pore at the summit of the body. Around this opening in the areas devoid of spines, are five little pores which are the openings of the reproductive system. In summer the eggs are cast out through these pores, and float in the water where they rapidly develop into little translucent larvfe with reddish spots, and provided with eight long processes which are rendered straight and rigid by calcareous rods. After swimming about, and devouring small creatures for several weeks the sea urchin suddenly develops in the posterior end of the larva, most of the body of which is absorbed and withers away in a few hours, leaving, upon the bottom, a minute globular sea urchin not larger than a pin's head. The Green Sea Urchin, fSirongylocentrotus di'ohadticnsis, Fig. 25 J, is found in the deep waters of Long Island Sound but north of Cape Cod it occurs in shallow tide-pools, and on the Maine coast it literally covers the rocks. It extends into the Arctic Ocean, and is found on the north' Pacific coast. It may be at once recognized by its resemblance to a greenish chestnut bur. The body is flatter than a hemisphere, about two inches in diameter and densely cov- ered with sharp pointed spines not more than three-eighths of an inch long. In some individuals these spines are tipped with dull violet. In addition to the spines, there are also a large number of little pincers mounted upon rod-like bases. These are used for the removal, or retention, of refuse material Avhicli may fall upon the sea urcliin. The five double rows of long, slender, tube-feet allow the animal to cling to the rocks over which it slowly glides in search of the algfe, and small organisms i;pon which it feeds. It often covers itself witli bits of seaweed and other fragments. The Stinging Urchin, (Diadema setosumj, is abundant along the Florida coast and in the West Indies, where it is often seen in clusters upon the sandy bottoms. These urchins are velvety black, about four inches in diameter, and are covered with sharp i:)ointed black spines, some of which are fully four inches long. These spines wave rapidly about upon the approach of an enemy, and if the urchin be seized, they penetrate the skin of the attacking per- son and break off, inflicting a most painful sting. 60 SEA-SHORE LIFE Fi^. 32: SAND-DOI-LAi;. When young the spines are banded with dark gray and white, but they become dark brown or dark purple in the adult urchin. The body of the urchin is sprinkled over with glistening blue eyes each one of which is provided with a number of prismatic lenses, a retina and nerves. The Sand D(^llar, (EcU- luii'dcliniuspcn-iiia. Fig. 32 J, is found in swarms upon sandy bottoms from New Jersey northward to the Arctic Ocean and the Pacific. It is flat with a rounded edge, about three inches in diameter, and dense- ly covered with short brown spines. The mouth is at the centre of the under side, while the vent is at the mar- gin. Radiating outward from the centre of the upper side one will see the slightly raised pattern of a five-rayed star, the borders of which are outlined by numerous little pores, through which gill-like organs project upward. The sand dollar is enabled to glide over the bottom through the action of its numeroixs sucker-like feet. When turned over on its back it is unable to right itself, however, and thousands are cast ashore by every great storm. An indelible ink is prepared from sand dollars by pounding them up in water. The Brittle Sea- Cucumber, fSynapta inhcprens, Fig. 33 J, lives in sand tubes within sandy or muddy beaches from the Carolinas to Cape Cod, and is also found on the coasts of Europe. At first sight it resembles a worm, but it is an Echinoderm closely related to the starfishes and sea urchins. Its body is liighl}' contractile, but when extended is about one-eighth of an inch in diameter and more than a foot long The creature is translucent with five white lines marking the places where muscle bands extend down the body. The skin is covered with little white dots that indicate the places occupied by minute calcareous anchors which enable the animal to obtain a hold when moving. The mouth is at the front end of the long worm- like body and is surrounded by twelve feathered tentacles. The coiled STARFISHES, URCHINS AND SEA-CUCUMBERS Gl intestine extends the entire length of the body, and may be seen through the translucent skin, especially when it is distended by the sand which the creature constantly swallows in order to obtain the minute organisms upon which it feeds. The Synapta lives within a tube made of fine sand particles aglutinated with adhesive slime. This tube is made up of a series of rings. The Sijmipta selects little particles of sand with its ten- tacles, and then fastens them together so as to form a ring around the mouth. The ring is then forced down the sides of the body by muscular • ,. contraction, and thus a tube is finally made with- in which the creature lives. Our Sjpiapta has the curious habit of break- ing itself into pieces by muscular constriction, and if placed in unfavorable conditions, it soon breaks up into numerous short lengths. A good figure of it is given in Agassiz's " Seaside Studies," under the name of Synapta tenuis. The Red Sea-Cucumber, (Synapta roseola), closely resembles Synapta inliaren^ but can be at once distinguished by its reddish color, and by the fact that it lives under stones or in gravelly beaches, never in sand or mud. The Crimson Sea-Cucumber, fCtivieria sqiia- mata J, is found along the New England coast north of Cape Cod. It is of a brilliant red color, and the sides and back are shingled with round-edged scales. The lower side of the body is free of scales, but is provided with three rows of tube-feet bearing suckers. There are ten tentacles which branch profusely and resemble beautiful red trees almost as long as the body. The creature becomes about eight inches long. The brilliant red larvae, about as large as a pin's head, occur in myriads in the ocean during the sirring and earlv summer months. Fig. 33; HIMTTLK SEA CUCLMBEK THE WORMS rr^HE worms include a large number of creatures which differ greatly one from another, both in form and in habits of life. They are found in almost every imaginable situation, although generally dependent upon moisture for their development. Many sorts of worms are parasites, and no animal is wholly free from their attacks. Although repulsive at first sight, worms are really among the most interesting of all animals, for a careful study of their develop- ment and structure shows that crustaceans, insects and mollusks are probably descended from worm-like ancestors. The flatworms or Platodes are among the simplest of all worms. The free-swimming flatworms are common upon seaweed-covered rocks, or upon dead shells. They are generally small creatures more or less leaf-shaped with the front end of the body bluntly rounded. They crawl or swim with a wave-like motion. The sucker- like mouth is upon the lower surface, never at the extreme front of the creature; and the intestine ends blindly, so that undigested particles of food are cast out through the mouth. Numerous little eye-spots and sensory hairs are often seen on the upper surface of the worm, and the nervous system is well develojDed. The brain is near the front end, and gives rise to two main nerve branches which extend down the body near the lower surface and are joined at regu- lar intei'vals by cross fibres, making a ladder-like arrangement. The flatworms often lay their eggs in cocoons or capsules, each cap- sule containing a considerable number of eggs, only a few of which develop ; the remainder being devoured by the successful larvae. The tapeworms and flukes are related to the flatworms, and are parasitic within many animals. The development of these para- sites is interesting, for example the tapeworm produces eggs which develop into little embryos, each with four or six hooks and suckers, and which are then cast out and die, unless accidentally swallowed by some other animal. In this event, however, the little tapeworm gets rid of its egg-shell, and bores its way through the wall THE WORMS 63 of the stomach of the animal, and lives somewhere within its body. The worm, however, does not usually grow to any great size or develop any segments, but remains little more than a "head" with hooks and suckers. If, however, the animal within which it is living be devoured by another, the little head is set free and attaches itself to the walls of the stomach of the new host, and then it grows to an enormous length, forming hundreds of segments which develop thousands of eggs, and are finally cast out one after another through the alimentary canal of the host. The highest of the worms are called ^innelids, for their bodies are ringed or divided by constrictions into a number of segments. The head segment contains the mouth and is often provided Avith feelers and eyes. Then follow a large number of body segments quite similar each to each. These often bear flapper-like side appendages which are both gills and feet. The posterior segment usually has one or more pairs of feelers. The intestine runs straight through the body from one end to the other, and the throat which is often armed with teeth, can be turned inside out. There is a well developed In-ain in the head segment and a chain of nerve fibres extends down the lower side of the body, with a knot-like mass of nerve cells in each segment. The eggs of many Annelids are cast out into the water Avhere they divide into a number of cells, and soon develop into little free-swimming larvre which are apt to be tack-shaped, the body being elongated, and the head broad and flat. There is a ring of waving cilia around the edge of the broad head of the larva, and another at its posterior end. The mouth is at the narrow edge of the head of the tack, and the intes- tine bends at right angles and runs entirely through the body, open- ing at the posterior end. There is usually a sense organ or brain at the centre of the head of the tack, and often we find sensory bris- tles or hairs at this place. Larvae of this sort are so common that a special name, trochopliora, is given to them. Soon the flapper-like legs develop along the sides, and the body becomes segmented and gradually changes into the form of the adult worm. But in addi- tion to this development from eggs many worms increase in even more interesting ways. For example, in some forms called Syllidce, we often find that eyes and feelers begin to develop at regular intervals upon certain segments of the body of the worm, and then 64 SEA-SHORE LIFE the original worm breaks up into a number of individuals each pro- vided with eyes and feelers. In the Palolo worms f Eunice J of the tropical Atlantic and Pacific oceans, the eggs are contained only in the posterior end of the worm ; and this end is cast off early in the morning of the day of the last quarter of the moon, at the Tortugas, Florida, in July ; and in the Pa- cific in November. This cast off end then swims upon the surface for about an hour, and finally contracts so as to squeeze out all of the eggs after which it sinks to the bottom and dies, leaving the eggs to develop, and the forward etid of the worm to regenerate a new posterior part. The Ribbon-Worm, (Meckelia ingens, Fig. 34J, is common in muddy or sandy beaches from South Carolina to Cape Cod where it lives buried beneath the ground near low water line. When fully stretched large individuals are about ten feet long, ])ut when con- tracted even tlie largest are not more than five feet in length. Com- monly the worms are not more than three feet long and about three- quarters of an inch wide, being flat and ribbon-like with bluntly pointed ends, and of yellowish-white color. The body is slimy and the skia is covered with minute cilia wliich wave constantly. These however can be detected only with the microscope. This worm is remarkably active and is an excellent burrower, ■forcing its way through the sand with considerable rapidity. It is also a good swimmer, throwing its ribbon-like body into sinuous waving lines as it moves through the water. When distiirbed it rapidly shoots out a long tubular proboscis which arises from a pit on the dorsal side of the head and is not a part of the throat. This proboscis is sometimes thrown out so violently that it breaks off, and then wriggles about very much as if it were a complete worm, while another proboscis is soon regenerated. The proboscis is coa^- ered with an adhesive slime, and serves in the capture of prey ; for this worm feeds upon other worms which it devours entire. The mouth is on the lower side of the head. The development of the ribbon-worms or Nemerteans is interest- ing. The larva is helmet-shaped with a broad head region, and covered with cilia which enable it to swim rapidly. After a time parts of the outer skin sink down in four pit-like depressions into the body of the larva and these grow together around the intestine, THE WORMS 66 and thus the little worm develops, as it were, within its own larva, which shrivels and is cast off. The Pink Rihbon-Worm, (Meckelia rosea), is snialle]' than .¥. iiujeiis, never being more than ahont ten inches long and one-quar- ter of an inch wide. It has a thread-like proboscis which can be Fig. J7/ upper. 1UB150X-WOKM. Loiver. OPAL-WORM. shot out with remarkable rapidity, and is I'uUy ten inches long. This worm is dull red or flesh colored, and lives in sand near low water mark. The sand adheres tenaciously to the slime-covered body of the worm. The Sea Mouse, f Aphrodite aculeata, Fig. S5). This remarka- ble worm is oval in shape, and about three inches long and one and one-half wide. The skin is dull brown but the sides are covered with numerous hair-like bristles, many of which glisten with brilliant green, red and yellow iridescence. The head bears a pair of tapering feelers, and there are abont forty pairs of legs provided with short, stiff, Ijrown- colored bristles, Avhich extend outward at the edges of the flat lower surface This worm lives in mud below tide level, and is found from Long Island northward, and is abundant on the northern coasts of Europe. The Clam Worms, (Nereis, Fig. 36 J, are very common in muddy beaches wliere tliey live between tide levels in burrows lined with mucous. They are segmented, or ringed, each ring of tlie body bearing a pair of flapper-like gill-feet. The head segment, however, is more complex, for it bears ten feelers, two fleshy "palps," and Fts:. SEA-MOUSE. 6;5 SEA-SHORE LIFE four black eyes. When disturbed the worm turns its throat inside out displaying a jjair of sharp, horny jaws. The posterior segment of the bod)' has no gill-feet but bears two long feelers. There are three species of clam worms to be found on our coast. The largest of these is Nereis virens which is even more abundant northward and extends to the northern coasts of Europe. It becomes Fig. j6; CLAM WORM From Life. Long Island Sound. about one and one-half feet in length, and the body is olive brown or olive blue with a beautiful pearly iridescence. The gills, which are attached to the upper sides of the feet, are leaf-shaped, and are green on the front and salmon red on the middle and hinder parts of the body. The teeth are black. Nereis liinhata is also common. It may be recognized by its horny, yellow colored teeth and small size, being not more than six inches long. Nereis pelagica is more abundant on the coast of New England north of Cape Cod. The body is widest in the middle, while in the other species of Nereis it is widest very near the head end. On calm nights, during the summer months, these worms leave their bai'rows, swim about near the surface, and cast their eggs out into the water, where they develop into little pear-shaped larva? which swim rapidly through the water by means of waving cilia. The development has been thoroughly studied by E. B. Wilson in "The American Journal of jMorphology," 1892, Vol. VI. Nereis is a carnivorous worm and greedily devours other worms, and various marine animals. It is, however, a favorite food Avith fishes and makes an excellent bait. It is also preyed upon by the ribbon worm. THE WORMS 67 The Opal- Worm, ( Lumhrieonereis opaJiiui, Fig. 34 J, is abund- ant in muddy Leaches from New Jersey northward. The body is ringed, and each ring bears a pair of bristled feet. It is about J^'^- .?/,■ HEI) THREAD WOKM. Long Island Sound. eighteen inches long and one-eighth of an inch wide in the middle, the ends gradually tapering. The head is simple and ])ointed, without feelers. The Avorm is of a rich bronze color with a brilliant play of opalescent colors over its surface. The Red Thread, f Lumhrieonereis tenuis, Fig. 37 J. A shovel J^ig, jS; FOUR-JAA\ED WORM. From Life. Long Island Sound. thrust into almost any of our muddy beaches will show that the mud is infested Avith slender, thread-like worms of deep dull-red 68 SEA-SHORE LIFE color, and about one foot in length. Tiiey are so fragile that it is extremely diliicult to dig them out unbroken. The Four-Jawed Worm, (Euglycera americana, Fi