The American Naturalist

Anthropology at the American Association, 740; Unsymmetric Lance points,744; The Anthro-
pological Society of Washington, 813; The Davenport Academy, 814; Anthropology in France,
815; Anthropology in England, 816; Biblography, 817; New Archæological Enterprises, 899;
Japanese Mythology, 902; Burial of the Dead, 904; The American Antiquarian, 904; Mound
Relics from Illinois, 905; Anthropological News, 905.

Geology and Palæontology.-Thickness of the Ice Sheet on its Southern Edge, 59; Were the

Ichthyosaurs Viviparous, 60; Miocene Fauna of Oregon, 60; Pliocene Man, 60; The Water

Sheds of the State of New York, 139; Geological Survey of New Zealand, 140; Hill's Kansas

Explorations, 141; Hulke on Ornithopsis of Seeley, 142; Filhol on the Fauna of St. Gerand le

Puy, 142; Notes on Sabre-tooths, 142; Fossil Crawfish from the Tertiaries of Wyoming, 222; On

the Sauropterygia of Boulogne-sur-Mer, 223; A new Hippidium, 223; Notes on the Androscog-

gin Glacier, 299; Marsh on Jurassic Dinosauria, 302; Archæopteryx, 302; The Manti Beds of

Utah, 303; The Skull of Empedocles, 304; A New Genus of Tapiroids, 382; The Structure of

the Permian Ganocephala, 383; Buthotrephis from York county, Pa., 384; The Comstock Lode,

384 Artificial Formation of the Diamond, 456; Corrections of the Geological Maps of Oregon.

457; A New Genus of Rhinocerontidæ, 540; The Geology of Southern Arizona, 541; Extinct

Batrachia, 609; The Genealogy of the American Rhinoceroses, 610; Halitherium capgrandi, 611;

A Genus in Anticipation, 611; Iguanodons, 612; The Geology and Topography of the Catskill

mountains, 612; On the Occurrence of Footprints of Dinornis at Poverty bay, New Zealand,

682; Geological Examinations in Texas, 684; The Bad Lands of the Wind river and their Fauna,

745; Geology of Egypt and of the Libyan Desert, 818; Vertebrate Palæontology of India, 818;

The Geology of the Lower Valley of the Delaware, 819; Origin of Coral Reefs and Islands, 819;

The Comptes Rendus Stenographiques," 820; Geological News, 821; The Devonian Insects,

905; America's Coal Supply, 907; The Northern Wasatch Fauna, 908; Geological News, 909.

Geography and Travels.-Hayden's New Maps of Wyoming, etc., 62; African Exploration,

64, 143; United States Geological and Geographical Survey of the Territories. Work of 1877-8.

Primary Triangulation and Yellowstone Park Maps, 223; The Interior of Greenland, 304:

Finsch's Expedition to the North Pacific, 306; Geographical News, 306; Asia, 385; Arctic

Voyages, 458; The Howgate Arctic Expedition, 460; The Voyages of the Willem Barents and

the Isbjorn in the Barents sea, 542; Circumpolar Stations-The Aurora Borealis, 544; Naviga-

tion of the Siberian Arctic ocean, 546; "Die Metamorphosen des Polareises," 548; The Ascent of

the Binué, in August, 1879, 686; The Royal Geographical Society's Expedition to Lakes Nyassa

and Tanganyika, 748; The Franklin Search Expedition, 821; Howgate Expedition, 824; Col.

Prejevalsky, 824; Proceedings of the Geographical Section of the British Association, 909.

Microscopy.-Improvements in Cell-cutting, 65; Another Journal, 68; Adulterations in Food,

68; Exchanges. 68; Thin Glass Slide Troughs, 146; Preparations of Crystals for the Polari-

scope, 146; Separating Foraminifera from Sand, 148; Naturalists' Directory, 148; Hints on the

Preservation of Living Objects, and their Examination under the Microscope, 225; Method of

Separating Organisms from Water, 227; Agency for Exchanging Objects, 309; Exchanges of

Apparatus, 309; American Society of Microscopists, 309; Observations on the Construction of

ths Huyghenian Eye-piece as used in Microscopes, 309; Organisms in Ice from Stagnant Water,

388; American Society of Microscopists, 389; Adulterations of Food, 461; A new "Growing

Slide" for Minute Organisms, 463; Collecting and Mounting Spiders' Webs, 454; Wood-fibers

for Paper-making, 465, Cleaning Cover-glasses, 465; Spodumene, 465: The Microscopical Ap

pearance of the Valves of Diatoms, 465; The American Journal of Microscopy, 465; Micro-

scopy at the American Association, 613; American Society of Microscopists, 613; "Science,"

613; Microscopists' Annual, 614; Holman's new Compressorium and Moist Chamber, 691;

Methods of Dry Mounting, 693; Permanent Microscopic Preparations of Plasmodium, 751;

Permanent Microscopic Preparations of Amphibian Blood, 752; Use of Collodion in Cutting thin

Sections of Soft Tissues, 825: The Atwood Cell, 825; Artificial Crystals of Gold, 826; Angular

Aperture, 827; Sweating of Microscopic Slides, 827; The National Societies, 912; New Local So.

cieties, 915.

SCIENTIFIC NEWS, 68, 148, 227, 311, 389, 466, 548, 614, 694, 753, 829, 915.

PROCEEDINGS OF SCIENTIFIC SOCIETIES, 71, 152, 232, 311, 390, 470, 552, 757, 831, 917.

SELECTED ARTICLES IN SCIENTIFIC SERIALS, 72, 152, 232, 312, 392, 472, 552, 616, 832, 919.

THE

AMERICAN NATURALIST.

VOL. XIV. JANUARY, 1880. No. 1.

OBSERVATIONS UPON THE HABITS, STRUCTURE AND DEVELOPMENT OF AMPHIOXUS LANCEOLATUS.

BY HENRY J. RICE.

REVIOUS to last season, specimens of that very curious fish

like animal, Amphioxus lanceolatus Yarrell, had been discovered along the eastern coast of the United States only in Florida and North Carolina, and one specimen, according to Mr. P. R. Uhler, president of the Maryland Academy of Science, upon the Eastern Shore of Virginia. While engaged in laboratory work at the Chesapeake Zoological Laboratory, at Fort Wool, last summer (1878), I was fortunate enough to obtain possession of three adults-two males and a ripe female-and twenty specimens of the young of this very interesting species, thus making Fort Wool not only a new locality for the adult animal, but, so far as I am aware, the only place in America where the young have ever been captured.

Of these specimens the adults were taken with the dredge from the bottom of the bay, south and east of the fort, in a depth of water of from twelve to fifteen feet, and the young were secured by surface dredging with small hand-nets of bolting cloth, from around the wharf, and near the steps of the boat-landing. While they remained alive, which was during the greater part of the months of July and August, I had the opportunity of making a very interesting series of observation, in regard to their habits, and those peculiarities of structure and development which have drawn so much attention to this animal, and rank it as at least the lowest of vertebrates, if not an intermediate type between Vertebrata and Invertebrata. These investigations, the results of which

VCL. XIVNO. I.

I have embodied in the following necessarily incomplete summary of our present knowledge of Amphioxus, were conducted with a great deal of care, and while they have led me to differ from the commonly received views in regard to certain particulars of structure and development, they have enabled me, by a somewhat detailed comparison of results, to corroborate much of what has already been done in this important field of research.

History. This apparently insignificant little creature was first made known to science, in the year 1778, from specimens found upon the coast of Cornwall, England, and sent to Peter Simon Pallas, a celebrated German naturalist, who was then issuing his Record of new forms of animal life. The description given in this Record' is, in the main, quite accurate, but from some misunderstanding of the nature of the ventral ridges, or perhaps from some slight resemblance to a sea-slug, Pallas considered it a new species of snail, and named it Limax lanceolatus. Had he had the opportunity of examining other than contracted specimens of this new form, he probably would not have written, "Tentacles evidently none," and might have hesitated before placing it among the Limacidæ. But if Pallas failed to correctly estimate its generic features, the next writer who mentions it seems to have been able to appreciate them to a certain extent, for he remarks, that it is "hardly a Limax," although for some reason he retained this name, and adds to it, probably through some typographical error the specific term of lanceolaris, which ought only to accompany the genitive of Limax, or Limacis. After this notice by Stewart, Limax lanceolatus seems to have dropped from the vocabulary of zoologists and to have passed almost from the memory of those engaged in describing and classifying new species of animals, for in 1834, when Costa3 discovered this same animal in the Bay of Naples, Italy, he failed to recognize it as having been described before, and considering it a new species of fish, he named it Branchiostoma lubricum, from the fact of its having tentacles about the mouth, and upon the supposition that these tentacles subserved the purposes of respiration as branchiæ.

'Spicilegia Zoologica. Peter Simon Pallas.

Berlin, 1778.

2 Elements of Natural History.

Fasc. x, p. 19. Taf. 1, Fig. 11.

Stewart. 2d edition. Vol. I, p. 386.

3 Cenni Zoologici ossia descrizione sommaria di talune specie nuove di animali. O. G. Costa. Page 49. Napoli, 1834. And, Storia el Branchiostoma lubricum. Napoli, 1843.

Almost simultaneously with this discovery of Costa, it was rediscovered upon the coast of Cornwall by Mr. Couch, and was recognized by Mr. Yarrell as the Limax lanceolatus of Pallas. But Mr. Yarrell also recognized as Costa had already done, and thus corroborating the doubts of Stewart, that instead of being a Limax it was, in reality, closely allied to the class of fishes, and not aware of its discovery in Italy, by Costa, he erected a new genus for it, Amphioxus (Amphi, on both sides, and oxus, sharp, from the fact that both extremities are pointed), and described it in 18361 as Amphioxus lanceolatus. It will thus be seen that the generic name assigned it by Costa has priority over that instituted by Yarrell, but the term Branchiostoma being founded upon a misconception of the functions of the tentacles, and the specific name of Pallas having priority over all, the name as given by Yarrell, Amphioxus lanceolatus, has come, by common consent, to be adopted as the appellation of this small denizen of the sea. Since 1836 Amphioxus has been found inhabiting nearly every quarter of the globe, specimens having been taken in China, Borneo, South as well as North America, and along the entire coast of Europe, although it has been found most abundantly in the waters of the Mediterranean sea, near Naples and Messina, Italy, where at present the conditions seem to be most favorable for its propagation and growth.

These various specimens, coming from such widely separated localities, were supposed, by their discoverers, to represent distinct species of this animal, and specific names have accordingly been given them, as Amphioxus belcheri Gray, for the East Indian form, and Branchiostoma caribæum Sundeval, for the form upon our coast, but the best informed European systematists consider that all these forms represent but a single species, the A. lanceolatus Yarr., of Europe, which thus becomes one of the most widely distributed, as it is certainly one of the most anomalous of existing animals.3

1 Hist, of Brit. Fishes. Wm. Yarrell. Vol. II, p. 468. London, 1836.

2 Traité de Zoologie. Page 808. Paris, 1878. Translated by Prof. G. MoquinTandon from the third and latest edition of the Handbuch der Zoologie of Prof. C. Claus.

Dr. Gill, of the Smithsonian Institution, informs me that Sundeval separated the Caribæan form from that of Europe on account of a difference in the number of plates, or fibers in the muscle-plates, of one form from that of the other. I have not as yet been able to examine the two forms with a view to determine this point.

General Description and Habits.-The adult Amphioxus, Fig. 1, Pl. 1, is a small, rather slender animal, which lives for the greater part of the time entirely buried in the sand along the sandy portions of the shores which it inhabits. When fully grown it is about two inches in extreme length, rarely somewhat longer, and of a pale flesh color which changes, when seen by reflected light, to a beautiful display of metallic iridescence.

Its body is smooth, very muscular, much compressed from side to side, and tapers gradually to the extremities, which are pointed, but differ considerably in contour, for while the posterior is lanceshaped, from whence is derived the specific name of lanceolatus, the anterior is formed like the ram of a modern gun-boat, and is admirably well adapted for forcing a way through the sand in which it burrows. The abdominal portion of this blade-like structure forms a dilatable sack which extends from near the anterior end of the body back for about two-thirds the entire length of the animal, where it terminates in an opening, the abdominal pore or branchiopore, which places the cavity enclosed by the sack in communication with the exterior. During the life of the animal this abdominal sack is seen dilating and contracting quite regularly, although at rather lengthy intervals, with a wave-like motion which begins at the forward end of the cavity and travels backward, rather slowly, to the posterior extremity. When the sack is completely distended this portion of the body presents a full, clear, rounded appearance, and projects considerably below the ordinary ventral outline, but when contracted, as it is in all preserved specimens, all appearances of a cavity disappear, leaving merely a slight indentation where the "pore" is situated, between the abdominal and the tail portions.

Through the center of the muscular part of the body, and forming an axial support to the animal, there is a long, slender, semi-cartilaginous rod, which is pointed at each end, and which extends from the very point of one extremity to that of the other. This rod is composed of an external membraneous sheath enclosing a series of closely approximated flattened disk-like bodies, and is probably the homologue of the vertebrate notochord, or backbone, although not exhibiting any anterior cranial expansion. Above it, but not extending quite as far forward, is the main nervous system, or chorda dorsalis, and below it lies the long, nearly straight alimentary canal. This canal opens anteriorly by a longitudinal

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