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closure. This circle is about fifteen feet in diameter. Another variety shown on the next engraving is a double circle, or rather two circles, one within the other, and about two feet apart, surrounding the stone cist. The stones in this example nearly

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touch each other. A somewhat similar one, but with the circles farther apart from each other, exists in the Isle of Man, and is shown on the annexed ground plan. The mound, in this instance probably rose from the inner circle only, and covered the central cist. In several instances the interment was not in the centre of the circle, but was made in different situations within its area. For instance, in the next example, from Trewavas Head, the cist is near

to the circle of stones, as it is also in the famous circle of Callernish. The outer diameter of the mound is thirty-five feet, the diameter of the circle of stones being nineteen feet six inches. Other examples, similar in arrangement, occur.

The next plan shows a totally different construction. In this instance the circle is composed of a number of stone cists, or sepulchral chambers, pretty close together, end to end. This curious example, of which

a somewhat analogous one exists in the Channel Islands (here

engraved), is on Mule Hill, in the Isle of Man. The next cuts show

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the plan of another pair of "twin barrows,” so-called, the circle in

the largest being about thirty-five, and the smallest twenty-four, feet in diameter. In the centre, at A B, are the remains of a stone cist, or chamber. « The mounds were both cairns of loose stones. Remains of other barrows, similarly formed,

in the vicinity. There were two within a few hundred yards of the “twin barrow” last described, the greater portions of which have been taken away recently to build a neighbouring hedge, but of which I found enough to show how they were built. First, there was an enclosing circle of stones, some placed upright, some

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longitudinally (see cut), the intention being simply to make an enclosing fence; within this the grave was constructed, then small

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stones heaped over the whole, the cairn extending, by about six feet, outside the built circle. The more perfect of the "twinbarrows,” also, had the cairn extending beyond the circle.

Some larger circles, such, for instance, as the Boscawen-ân circle, eighty feet in diameter, the Aber circle (of which plans are here given),

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and others, it is supposed, may have been formed around a group of interments, instead of single interments, as in many of the others. In some instances, a single stone was placed to mark the place of interment. Three such existing in the barrow at Berriew (see cut).

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A large circle (here engraved) twenty-seven yards in diameter, on Penmenmawr was constructed by several uprights connected by smaller masonry. Here the interments were apparently made beside the pillars. Against the inner side of the tallest pillar, A, on

the eastern part, were the remains of a small kistvaen; while against the pillar B, facing it on the opposite side, was heaped up a small cairn. The whole is surrounded by a ditch, within which, at C, is another small cairn.

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A view of Arbor Low in the High Peak of Derbyshire, to which allusion has been made, is here given. No sepulchral remains have been discovered in the circle, but barrows of great extent, which have yielded important remains on being excavated, are closely connected with it. It is, however, possible that interments have existed, and been removed in past ages.

In the centre of the circle, which is about fifty yards in diameter, are some large masses of stone, which it is possible may have formed portions of a cromlech. The circle is formed of a number of immense stones, all of which, now remaining, lie flat on the surface, not upright, as in many other instances. There is every probability that such was their original arrangement. The circle is surrounded by a rampart and fosse—the fosse being of considerable width, about eighteen feet, and the rampart about six or eight yards in height from its inner base. There are two entrances to this circle, north and south, each of which is some considerable width. Close to the southern entrance is a large sepulchral mound, and about three hundred yards away, and connected with the embankment around the circle by a continuous embankment of earth, is another sepulchral mound, Gib Hill, which on examination has yielded, like the one at the entrance, many highly interesting features.

Sufficient has, perhaps, for my present purpose, been written to show that most or all of the lesser circles have been formed in connection with interments. Of the larger erections more may be said on another occasion.

ANATOMY OF THE STENTORS.

(With a Tinted Plate.)

THERE are no infusoria more beautiful or more generally attractive to observers than the Stentors, well known to all microscopists so far as their more obvious characters are concerned, but which present considerable difficulty when it is desired to make out their details of structure.

It is only by the frequent examination of a great number of individuals, and making the most of fortunate opportunities, that the various organs can be distinctly seen, and no disappointment should be felt if many efforts have to be made before success is achieved.

Drawings exhibiting anatomical details are almost invariably the result of combining in one view parts that cannot be simultaneously seen in the living animal. One Stentor, for example, may at one time show the mouth or gullet well, while the nucleus is scarcely visible, and some other

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cannot be seen at all. Another time the nucleus may be prominent throughout more or less of its length, and a complete delineation can only be made by putting together the information obtained in a long series of observations. Microscopists who are not aware of this fact are not only puzzled, but discouraged by the wide difference between what they see and what they find drawn by other folks. The only remedy against disappointment is patience, and a knowledge of how to use the figures which the best authorities publish. Those which we have now copied from Stein's great work “Der Organismus der Infusionsthiere ” will, no doubt, help our readers in their researches. They must not expect to see too much at any one time, and though very considerable reliance may be placed upon the figures, there may be some things to correct, and it is certain there is still a great deal to be learnt.

Stein describes the Stentors as "heterotrichal infusoria, with elongated rounded bodies, funnel-shaped in front, and remarkable for rapid changes of form ; with their hinder end, at the will of the creature, able to anchor it, or fix it to the bottom of an unattached case. The peristome is terminal, and occupies the whole of the anterior extremity; its margin is deeply indented or bent in the middle of the ventral side of the animal; the peristome margin is thickly ciliated; the mouth lies in the deepest part of the peristome field ; the anus is in the left wall of the body close behind the peristome. The

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