lists, are Niagara; next in number come those common to both, after which will be found the Clinton and characteristic species:

Discina solitaria (n. sp.),

Leptana sericea var. intermedia (n. var.).

As will be seen there are three species which have been considered to pass out of existence with the Clinton, that still survive in the stratum under consideration; unless we should also include the Leptæna described below.

Meristina intermedia has been placed in the list of species common to both groups, as the one from the Transition stratum, as well as those from the Clinton, are indistinguishable from specimens found in the Niagara shale; the only perceptible difference being a gradual falling off in size as we advance upwards in the series, and a slight diminution of the average width, so that Some from the Niagara approach closely to the typical M. nitida, although others will be found that are fully as wide as those from. the Clinton.

In all probability M. nitida and M. oblata are descendants of

M. intermedia; one branch developing in width while the other became narrow and elongate.

Thus far no Meristinæ have been found with a pronounced mesial fold, of which M. naviformis of the Clinton, and M. maria of the Niagara may be considered as types, although an intermediate form will, I think, be found.

The three specimens of Stephanocrinus gemmiformis found, all show a marked angularity of form similar to some young S. angulatus.

A Leptæna occurs in this rock that seems to be intermediate between L. sericea and L. transversalis, which it resembles in the convexity of the dorsal and the concavity of the ventral valves, while in texture, which is punctate and not so strongly striate as in L. transversalis, and by its wide lateral alation, it is more closely allied to L. sericea. Therefore I propose the name Leptæna sericea var. intermedia, as it undoubtedly represents the stage through which L. sericea passed before developing into what is known as L. transversalis.

The Atrypa nodostriata found here does not have so prominent a mesial fold as the Niagara forms, it being more gradual, and but little more pronounced than is found to be the case in gibbous specimens of A. reticularis from the Clinton.

Other species show slight variations from the Niagara types, or perhaps, more properly speaking, the types vary from the transition species.

Thus it will be seen that in many ways this apparently unimportant thin stratum, with its limited areas, that has been overlooked by the hundreds of geologists that have traversed this farfamed geological field, who probably have been lured from greater palæontological wealth by the tempting display of finely weathered-out fossils on the shale banks immediately above, as well as discouraged by the difficulty of wrenching the treasures from its flint-like grasp, plays a very important factor in the connecting chain of paleontological evolution. It binds together in closer unity two formations by its intermediate character, and also by the blending in it of forms before considered characteristic of these two well-defined groups.

Discina solitaria (n. sp.).—Shell oval, ventral valve with prominent apex; slope convex, slightly incurved near the apex on the posterior side; strongly marked by recurved concentric laminæ, of which, near the apex, there are about eight to oneeighth of an inch; these grow more crowded, wider and less recurved as they ap

proach the margin, where they project from the surface on a plane with the valve and lie one against the other; these lower lamina, when magnified, present a deeply wrinkled and furrowed appearance; these furrows are irregular, and proceed from the shell, growing fainter at the margin of the laminæ, and are scarcely perceptible unless the laminæ above are broken, apex about two-fifths of the length from the anterior edge; length, seven-eighths inches, width, six-eighths inches; height of apex

2.

e.

C.

d.

Discina solitaria (n. sp.)—a, ventral valve, nat. size; b, ventral valve, lateral view, nat. size; c, ventral valve, anterior view, nat. size; d, undulate surface of lamina from near the edge, enlarged; e, recurved laminæ from near the aperture, enlarged.

one-fourth inch. Foramen commences at the apex and extends half way down the side; shell barely incurved at this point, laminæ continuing without interruption to the edge of the apex here.

NOTE. Since the above was written I have succeeded in procuring a young specimen of a Meristina with a mesial fold. It appears to be closely allied to M. maria, and it has consequently been placed in the Niagara list until other specimens are found which will determine its relationship more clearly.

:0:

HYPNOTISM IN ANIMALS1

BY D. W. PRENTISS.

Mesmerism, or more properly hypnotism, has been recognized under various names in the history of all nations.

The same influences which work the modern phenomena of hypnotism are undoubtedly identified with the manifestations of magic found described in ancient history. The magic of Zoroaster, the wonderful performances of the magi of the East-among the ancient Persians, Hindoos and Egyptians-the spells and incantations of the Grecian and Roman oracles, the methods of divination, the remarkable feats of the snake charmers of India and Egypt, all belong to the same category.

And so also might we include the more recent wonderful manifestations of religious mania which swept Europe in the seventeenth century as an epidemic, known as the "dancing mania," and was literally a national calamity. In our own country it was Read before the Biological Society of Washington, D. C., March 31, 1882.

represented at the close of last century by the witchcraft of New England, and still later within the memory of men now living. by the "convulsive" and "laughing" mania among the Methodists-notably in the State of Kentucky, where it is said that on one occasion as many as 5000 persons in camp meeting were under the "influence" at one time. The victims fell in convulsions and soon passed into a state of ecstatic trance, and were laid out on the grass in rows to recover themselves.

Physicians are brought in contact continually with similar conditions as forms of disease, under the names of hysteria, catalepsy, ecstacy and lethargy. No more marvelous stories can be found in the whole range of fiction than are presented as sober matters of fact in the standard works on nervous diseases—such as of Charcot, Weir Mitchell and Hammond.

In this place are to be classed the modern miracles of the Church. The history of "Our Lady of Lourdes" finds an exact parallel in many of the cases that have been lately so thoroughly studied at the Hospice Salpetriére in France, by Chalcot. . All of these phenomena may be grouped into a single allied genus, of which the various forms of manifestation may be considered species. Mesmerism is one of the species, clairvoyance and modern spiritualism may be mentioned as others. No systematic or scientific attempt was made to study into the nature of these phenomena until the time of Mesmer, from whom this term is derived.

Mesmer was a German physician who went to Paris in 1778 to practice his new discovery of "animal magnetism" in the cure of disease. In six years he amassed a large fortune, and during that time kept Paris in a fever of excitement with his doings.

In 1784 a royal commission was appointed, of which Benjamin Franklin was one, to investigate his methods. Their report was unfavorable to the claims of animal magnetism, and Mesmer's popularity soon declined.

Mesmer's exploits in Paris are designated by Mills as the first epoch in "mesmerism."

The second epoch is that of Braid, an English physician, 1841. Braid disclaimed anything like animal magnetism in his operations, and explained them by referring to physiological and psy chological influences in the subject.

He gave the name of hypnotism to the phenomena produced,

and like Mesmer applied his skill to the treatment of diseases; the diseases claimed to be influenced favorably being neuralgia, hysteria, epilepsy and the like. Surgical operations were also performed painlessly during the anesthesia of the hypnotic state. Teeth pulling, excision of mamma, and even amputations of the thigh, are among the operations performed. Braid published a voluminous book upon the subject, relating his views and expe

riences.

The third epoch of Mills we are now passing through. The experiments and writings of Heidenhain of Germany, of Charcot and Richer of France, and of Beard, Hammond and Mills in this country, have revived the interest in the subject, and hypnotism is again being subjected to a rigid scrutiny.

The subject is one of great interest in itself, not only from a scientific standpoint, but also from the fact that more precise knowledge of the laws governing the phenomena presented may be of practical value. That hypnotism has been used with apparent benefit in the treatment of certain diseases, appears in the experience of many writers upon the subject, and it is certain. that the anesthesia thus induced may be taken advantage of for the performance of surgical operations. Recently in an exhibition by Dr. Hammond before a medical society in N. Y., a tooth. was extracted without pain, and a subject was burned with a red hot iron without conscious sensation. If the application of hypnotism could be reduced to a science, it is among the possibilities of the future that it might supercede the use of such agents as chloroform and ether as anæsthetics.

In the present state of knowledge, however, this is impracticable, as well also as its use as a therapeutic agent. Although the subject has engaged the attention of investigators for centuries, no acceptable explanation of the manifestations of mesmerism. has yet been offered.

Undoubtedly a large proportion of the acts shown in public exhibition are due to trickery and collusion, but I think no one can witness such an exhibition as was recently given in Washington, by Carpenter, without feeling that all is not deceit, that there is an influence at work which thus far has not been fathomed.

Mesmer called it animal magnetism, and claimed it to be an emanation from his person, as electricity from a battery.