ersky touching the startling vertebrate features of the early condition of these invertebrata. He reserves for the present the details about the exact formation of the nervous system, but quite confirms the fact of the existence of a notochord. He says: "At this stage one could not imagine a more beautiful model of a vertebrate embryo, with the neural tube on one side of the axis and a visceral tube on the other." He, moreover, describes in his species of Phallusia the neural tube as not merely an almost spherical vesicle, but as prolonged in the form of a fine hollow thread into the tail above the notochord or axis. He promises full details shortly, and we hope to be able to return to this most important matter. Nature, London.

HOUSE WRENS.-I have had the pleasure of being acquainted with these little birds (Troglodytes ædon) for several years. They have bred in and around my house, until they have become so tame as sometimes to allow the children to handle them. They have become so numerous that I do not furnish boxes for all, and they make nests in many singular places; among others, in a bullet-pouch up chamber, a soldier's knapsack in an outbuilding. In both of these places the birds succeeded in rearing a brood. But the most singular place selected for a nest was the wooden stirrup of a saddle hanging in a shed, in which, however, the birds did not prosper, as the saddle was often used. They carried small dry twigs and other rubbish, consisting of pieces of steel wire, dried snakes' skin, etc., into the knapsack, enough to have filled a half bushel measure, filling the entire cavity, except a little corner which they lined with feathers, where they laid seven or eight eggs. I also noticed their superior instinct, if not reason, whilst building in a box near my kitchen door. The hole in the box would not admit the long twigs the birds tried to get in, and they fell to the ground. After many efforts and failures the wrens concluded by making a scaffolding, which they succeeded in doing by taking in several shorter sticks endwise, letting the ends project out of the hole; then they proceeded by laying the long twigs on these projecting ends, then getting into the box, and by sliding the long twig endwise until the end came opposite the hole, they pulled it in. I was amused to see one trying to carry a large nail heavier than itself. They are amusing little fellows in many ways. Their song is melodious, loud and clear, and I have often wondered that such loud music could be produced by anything so small. — Wм. J. MCLAUGHLIN, Centralia, Kan.

DEEP SEA DREdging off the BRITISH ISLES. — Our Admiralty, at the instance of the Royal Society, placed a war steamer at its disposal for sounding, dredging, taking deep sea temperatures, and making other physical investigations. The steamer left about the middle of May; and I had charge of the expedition for the first cruise of two months. Prof. Wyville Thomson succeeded me; and Dr. Carpenter followed. We dredged at depths varying between ten and two thousand four hundred and thirtyfive fathoms, everywhere getting mollusca, crustacea, and other inverte

brate animals, in a living state. This expedition embraced the Atlantic Coasts of Ireland, the Hebrides, and Shetland. There was not any trace or indication of the Gulf Stream, but on the contrary, a northern fauna even as far south as Ushant. Many novelties occurred.-J. GwYN JEFFREYS (in a letter to one of the editors).

THE KINGFISHER'S NEST. -I have watched with some interest all that has been said in the NATURALIST about the breeding habits of this species, to see if my experience would be justified by that of any other observer. This has been nearly accomplished by Mr. Jones in the March number.

On the 18th of March, 1868, I collected eggs from two nests built near a mill-pond, in the excavation for the dam. Each hole was three feet deep; one elbowed to the right, the other to the left. In one was six eggs, in the other seven; all fresh. Each nest was composed of dry fish scales and small dry fish bones mixed with small pebbles of the size of a small pea. The scales and bones were free from smell, and were white and pure, and in each nest amounted to a fair handful.

About the first of June, 1869, on landing from a fishing excursion on one of our small lakes, I observed what I took to be a kingfisher's hole in a sandbank on the shore. While my bait and tackle were being loaded, I took a paddle and began to dig it out. The sand was soft and I proceeded five feet very rapidly, when the bird came rushing out. I went on digging with renewed hopes and made seven feet, when the paddle was no longer available for insufficient length, and I abandoned the job.-D. DARWIN HUGHES, Marshall, Mich.

SPECTRUM OF THE FIRE-FLY.-The spectrum given by the light of the common Fire-fly of New Hampshire (Photinus?) is perfectly continuous, without trace of lines either bright or dark. It extends from a little above Fraunhofer's line C, in the scarlet, to about F in the blue, gradually fading out at the extremities. It is noticeable that precisely this portion of the spectrum is composed of rays, which, while they more powerfully than any others affect the organs of vision, produce hardly any thermal or actinic effect. In other words, very little of the energy expended in the flash of the Fire-fly is wasted. It is quite different with our artificial methods of illumination. In the case of an ordinary gas light the best experiments show that not more than one or two per cent. of the radiant energy consists of visible rays; the rest is either invisible heat or actinism; that is to say over ninety-eight per cent. of the gas is wasted in producing rays that do not help in making objects visible.-C. A. YOUNG.

DEATH OF B. D. WALSH.-We regret to record the death of Mr. B. D. Walsh, the State Entomologist of Illinois, and the Senior Editor of the "American Entomologist," and former Editor of the "Practical Entomologist." For these duties he was admirably fitted. As an enthusiastic and thorough naturalist the small band of entomologists in this country will mourn his loss.

GEOLOGY.

A FOSSIL TUBULARIAN. -Dr. P. Martin Duncan has discovered, conjointly with H. M. Jenkins, a new genus of tubularian Hydrozoa from the Carboniferous formation. It is called Palæocoryne, and was described in a paper read at one of the late meetings of the Royal Society. Palæocoryne is a new genus containing two species, and belongs to a new family of the Tubularidæ. The forms described were discovered in the lower shales of the Ayrshire and Lanarkshire coal-field, and an examination of their structure determined them to belong to the Hydrozoa, and to be parasitic upon Fenestrellæ. The genus has some characters in common with Bimeria (Str. Wright), and the polypary is hard and ornamented. The discovery of the trophosome, and probably part of the gonosome of a tubularine hydrozoön in the Paleozoic strata brings the order into geological relations with the doubtful Sertularian Graptolites of the Silurian formation, and with the rare Medusoids of the Solenhofen stones. - Popular Science Review.

ANSWERS TO CORRESPONDENTS.

A. E. T., Springfield, Ohio. Your aquatic plant is a Bladderwort (Utricularia intermedia), one of many species found in the United States in ponds, either floating free or rooting in the mud on the margin of the water. The name is derived from the little bladders which support it in a floating condition. The flowers are very pretty, usually yellow, but in some species purple.-J. L. R.

S. M. C., Otisco, N. Y.-The best work on American Neuroptera is Hagen's Synopsis of the Neuroptera, published by the Smithsonian Institution. It may be had at the Naturalist's Book Agency, The best account of our Orthoptera is to be found in Harris's Treatise on Insects Injurious to Vegetation. The Smithsonian Institution have also recently published Mr. Scudders List of Orthoptera, which is very necessary for the student. We have observed eaterpillars infesting herbaria in winter. Please send us a specimen of the Eudryas grata-like pupa found boring into the side of the wood, so that we can determine what it is. We did not know that Vanessa Antiopa fed ou Indian corn, or that Edema concinna fed on the poplar. These caterpillars will sometimes change their food plant.

R. B., Newberne, N. C.-The spiders are Epeira riparia Hentz, and E. cancer Hentz, The eggs of the latter, enclosed in a greenish yellow cocoon, hatched out in October. The young were of the rounded form of E. vulgaris, differing greatly from the angular, spiny, transversely oblong form of the adult.

Mammalia of Massachusetts. By J. A. Allen. Bulletin of the Museum of Comparative Zool. ogy. No. 8. Cambridge, 1869. 8vo, pp. 143-252.

Address delivered on the Centennial Anniversary of the birth of Alexander von Humboldt, under the auspices of the Boston Society of Natural History, by Louis Agassiz. Boston, 1869, 840, pp. 107.

Preliminary Report on the Echini and Star-fishes dredged in deep water between Cuba and the Florida Reef. By L. F. de Pourtales. Prepared by Alexander Agassiz. Bulletin of the Museum of Comparative Zoology. Cambridge. No. 9. 8vo, pp. 253-361. Cambridge, Nov 1869, Bulletin Mensuel de la Societe Imp. Zool. Acclimatation. Sept., Oct., and Nov., 1969. 8vo, Paris.

On a New Californian Terrestrial Molluse. By J. G. Cooper, M. D. 8vo. pp. 2.

On the Distribution and Localities of West Coast Helicoid Land Shells, etc. By J. G, Cooper, M. D. Syo, pp. 39. (From the Amer. Journ. Couchology, 1869).

Index to Vol. rii and Supplementary Inder to Vols, i to xi, of Observations on the Genus Unto, etc. By Isaac Lea, LL. D. Phila., 1869. 4to, pp. 23.

The Pathology of Bright's Disease. By W. B. Lewis, M. D. With Illustrations. New York, 1869. 8vo, pp. 29.

Science Gossip. November and December. London, oder Fora querie

Scientific Opinion. November and December. London.

Le Naturaliste Canadien. November and December. Quebec.

THE

AMERICAN NATURALIST.

Vol. III.-FEBRUARY, 1870.—No. 12.

SKATES' EGGS AND YOUNG.

BY F. W. PUTNAM.

IT is an interesting fact that while the class of bony, or true Fishes, both fresh water and marine, are, with very few exceptions, oviparous, and lay immense numbers of eggs, the Selachians, or sharks and skates and their allies, are, with equally few exceptions, viviparous, and bring forth but few young at a time. One of the exceptions to the rule of viviparity among the Selachians is the genus Raja, to which our common species of skates and rays belong. Though the fact that skates lay eggs has been known for centuries, still to this day there is probably no class of objects picked up by the wanderer on the sea beach that excites curiosity so much as the egg cases of the several species of skates, after he has found out what they are. On being seen for the first time, and before close examination, I venture to 'state that the majority of persons regard them as some vegetable production, and pass them by as the supposed "bladder" of the seaweed with which they are often so closely connected by their tendrils as to have the appearance of being part of the plant, which they also greatly resemble in color and general appearance.

Some sharp eyed fisherman long ago, ascertaining that the

Entered according to Act of Congress, in the year 1869, by the PEABODY ACADEMY OF SCIENCE, in the Clerks Office of the District Court of the District of Massachusetts.

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queer shaped things which he found on the Beach were in fact little pockets, or sacks opened at one end, not knowing what else they could be, concluded that in some way they must be connected with the "maids of the ocean," and what more natural than to suppose them to be the purses to hold the pearls and other valuables of the mysterious maids? and what better name than "Mermaid purses" could be desired? From this first christening, and following the common rule adopted for such cases—that of keeping as far away as possible from the real nature of the objectthey have been called, and are generally known as "sea purses" and "sailor's purses." The only popular name bearing on their real origin is that given to them on some portions of the English coast, where they are called "skate barrows," from their resem blance in form to a hand-barrow, and the knowledge of the christener that they were produced by the skates. 07 đi ji

As common as these egg cases are on our beaches, it is very seldom, and only at certain seasons, that they are found containing the egg or embryo. When fresh and filled by the embryo they are plump and swollen and of a much lighter olive color than when empty, dry and shrivelled. As long as the embryo is in the case no opening to the pouch cai) he detected, until just at the time when the young skate is to make his way into the world and commence his struggle for existence consisting principally in keeping himself from going into the ever ready mouths of his own kin of fin, tơ whom he forms a tempting morsel. Just as incubation comes to a close, then, the substance at one end of the casŐ Softens and the upper and under layers are pushed apart by the young skate who "noses" his way out; the two layers then spring back into place and the case on drying shows no sign of an opening, unless it is again softened and the layers carefully separated.998 97ed ende bus eotda olen siT boWe do not yet know the breeding season of our species, but Pennant in his "British Zoology," states that their skates generate in March and April, at which time they swinginear