two long pinulæ, the third and fourth pairs tened to any part presented, and crawled to having an extra recurved pinula; while the its place near the pectoral fins. I have reathird, fourth and fifth pairs are three-son to believe that it may also occupy the jointed, the sixth is obscurely two-jointed, gill cavities. I have left individuals alone with an appendage at base, these appendic- in a glass of water five days without any ular lobes slightly curved backwards, obtuse, apparent loss of vigor. reaching to the margin of the abdomen, covered with hairs.

The blood circulation is very well seen at many points, especially about the eyes and Color light yellowish green, upper part at the margins of the abdominal lobes.

FIG. 2. al, antenna of first pair; a2, antenna of second pair; a3, antenna of first pair, the corresponding one of second pair removed; e, eye; sh, siphon; am, ambulatory legs; h, hooks; s, spiculum.

of body blotched and streaked with violet brown. Length of female .36 of an inch, greatest width of carapace .19 of an inch.

Of several individuals obtained all were females.

The current passes down the inner margin, around the apex and up the outer margin; at intervals along the outer edge lateral currents are given off, which seem to occupy blood vessels proper. The corpuscles are small, The favorite place for the parasite to apparently spherical and not numerous. fasten is immediately back of the pectoral The striped muscular fibres moving the fins of its host. It often left the fish and legs and antennæ can be very clearly made swam about the tank, then returning fas-out with an inch objective.

The species of this genus are indeed cording to this plan the Rhizopoda are armicroscopical and zoological gems whose ranged under three heads, as follows:

value is not enhanced by their rarity.-Bulletin of Buffalo Natural Science Society.

No definite nucleus,
No contractile vesicle,
Definite nucleus,

No contractile vesicle,
Definite nucleus,
Contractile vesicle,

HERPNEMATA.

PROTODERMATA.

PROTEINA.

Since Dr. Wallich's paper was published, there have been discoveries made which would necessitate some changes in his table (e. g. the discovery of a nucleus in some of the Foraminifera would change these organ isms from the Herpnemata to the Protodermata) and we may well suspect the presence of nucleii in all these forms, although not

At any rate the form in question is one of considerable interest, in that it seems to occupy an intermediate position between yet demonstrated. the Lobosa and the Reticularia of Carpenter.

While it may appear from this that Dr.

1,000

Fig. 1. X .280.

It also tends to show that the classification | Wallich's classification leaves much to be of Dr. Carpenter, admirable and useful as desired, it still seems much more commenit has been, is not destined to be permanent, surate with present requirements than does nor would any naturalist consider for a the old division, into Lobosa Reticularia, moment that any truly scientific or natural Radiolaria and Spongida. As regards the classification could be based on the character of the ectosarc.

Indeed Dr. Carpenter himself, with characteristic foresight, only offered his arrangement for temporary nse.

form now under consideration, the figures will give a fair idea of its appearance. This notice is merely intended as a preliminary description, for the amount of material was quite limited, and some obscure points, It has served its purpose well, and it will such as the presence or absence of nucleus be long before any better classification of or contractile vesicle I have been unable to the rhizopods will come into general use determine. The great obstacle to this was among microscopists. Still, there has been the opacity of the test. However, as soon offered a plan which seems to the writer as opportunity offers I shall procure more much better. This is the classification pro- of them, and continue their study with posed by Dr. Wallich some time ago. Ac-reference to these points.

In Fig. 1 is shown the animal as first In Pleurophrys the pseudupodia are nuseen; the outline of the test was drawn with merous and come out in a mass. the camera under a power of 280 diameters. Among the Lobosa we have Trinema, in The pseudopodia were withdrawn at the which the pseudopodia are limited to two time, and I have not been able to catch or three, but they are not the same in charthem since in a suitable position when I acter as those of the one here described, could draw them in this way, so they are which are decidedly reticularian and filidrawn from memory as first seen.

form.

The description may be given as follows: It seems that this new form occupies a Test oval, more or less rough, with project-place between the Reticularia and the ing particles, yellowish, translucent or Lobosa, showing at times an extrusion of opaque; mouth usually terminal, sometimes sarcode resembling Lobosa, at others the slightly pouting or elongated; pseudopodia exceedingly attenuated filaments charactervery hyaline, very fine, only seen by careful istio of the Reticularia, and at still other focusing, not numerous (generally only two times both types of structure are seen at or three), very long, often three or four once.

times the length of the test; granules very I would suggest as an appropriate name minute and active, moving rapidly up and for this Rhizopod, and one which expresses down the pseudopodia, often in both direc- its relation to the two last named orders, tions at once on the same branch. The sar- and also its habitat, Lobularia marina. code is often extruded, so as to resemble 8 Beekman Place, New York, Sept. 18, 1877. the pseudopodia of Lobosa in a primitive form, in which case fine threads may be given out from this (see Fig. 2 and description.)

Hab. salt or brakish water near Pelham Bridge, N. Y.

Fig. 2 represents the mass of sarcode extruded in such a manner as would lead one

THE

Cox's Self-Centering Turn-Table. HE microscope can hardly be more than a toy in the hands of a person unable to prepare objects for examination. Its highest usefulness is in original research, and the real investigator is necessarily a preparer and preserver of specimens. Hence instruments for microscopical "mounting" are almost as important as instruments for observation. The AMERICAN JOURNAL OF MICROSCOPY has therefore always endeavored to give a due share of attention to mounting apparatus, and, in pursuance of this purpose, has several times published illustrations and explanations of improved forms of turn-tables. Although we have devoted considerable space to this particular accessory of the microscope, we feel that, in justice to the subject, we must present to our readers a description of C. F. Cox's self-centering turn-table, heretofore incidentally referred to in our pages.

Several turn-tables have been devised

which will centre a slide as to its width only, the most effective of these being probably the form devised by Dr. J. Matthews,

exhibited by him to the Quekett Club, de- perhaps more generally useful and pracscribed in Science Gossip for July, 1870, and tical. It was first described in the Monthly afterwards illustrated and commended in Microscopical Journal for March, 1875. By the second edition of Thomas Davies' work one of those curious coincidences which on mounting. In Science Gossip for Janu- often occur in the scientific world, Mr. C. ary, 1876, it was announced that Mr. Charles Mason Kinne, of San Francisco, was workButterworth had exhibited to the Oldham ing upon essentially the same idea at about Microscopical Society a turn-table, by the aid of which cells could be made with the utmost precision and despatch, and that, too, not only in the circular, but also in the elliptical form, of any size from 2 inches in length by 1 inch in width, reducible until a perfectly straight line was produced; but this ingenious contrivance must have been too complicated or too expensive for general use, for we have heard nothing more of it.

the same time, although we have reason to believe that he and Mr. Cox had never met,. nor heard of each other's self-centering apparatus, prior to Mr. Cox's announcement of his invention in 1875.

Cox's self-centering turn-table is, in its general form, similar to the common Shalbot turn-table, long in use with microscopists, as is evident from Fig. 1; but, to accommodate the centering appliance, it is necessarily a little larger, the brass revolvMr. Cox's invention is intermediate to the ing plate being about 4 inches in diameter. two just referred to, both as to the time of Fig. 2 represents a perpendicular section its announcement and as to the purposes through the line of the milled-head and accomplished by it. It does more than Dr. spindle. The glass slide is grasped, at two Matthews' turn-table, and somewhat less opposite corners, by right-angled clutches than Mr. Butterworth's, and is therefore C C, which are attached loosely by screws

may be wiped off and the cover will be found in the right position to receive a neat and accurate ring of varnish or paint.

to lugs which move upon the spindle S S, the object and the cover-glass. When the which is cut into right and left hand screws, balsam or jelly has hardened, and the slide so that when the milled head M is turned, is ready for finishing, this temporary ring the lugs move towards or recede from each other at a uniform rate, guided by the slots cut through the table on a line with its exact centre. The clutches turn so easily It is hardly fair to require improved upon the screws which attach them to the forms of scientific apparatus to conform to lugs, that they adapt themselves, without the defects of the apparatus it is intended assistance, to a slide of any shape approxi- to supersede, but unfortunately in the case mating to rectangular. The size of the of this turn-table the chief objection that slide which can be centered on this table has been made to it is that it is too accurate depends upon the play allowed the clutches to be of service in refinishing inaccurate by the length of the slots, but there is no work; and so Mr. Cox has adapted to it a difficulty in making a table of 4 inches spring-clip, which may be put on or taken diameter which will centre any slide from

11 inches square up to 3 by 24 inches.

One of the advantages of the right and left screw is that it is sufficiently unyielding to afford a firm hold upon the slide, so as to enable one to turn down or smooth off hard cells, as in a lathe. But, aside from this, it seems to us that it must be more accurate in its operation than any other device for moving the clutches could be.

It is manifest, from what has already been said, that the point of revolution of the slide as it lies upon the table must be the exact middle of its diagonal, and this, with a rectangular slide, will always be the true

Fig. 3.

This ar

the purpose of repairing old slides which
have not been truly centered.
rangement is shown in Fig. 3.

centre as to both width and length. This off in an instant, thus temporarily convertsecures perfect concentricity in finishing ing his table into the unimproved form, for and establishes a standard of nice work; for no matter how many applications of cement or varnish it is necessary to apply, the slide always assumes the same position on the By the addition of two brass triangles, table, and the different layers must there- the right angles of which are placed in the fore coincide. Moreover, work done by a clutches, so that the opposite sides press preparer upon one of these tables may al- upon and hold the glass slide, as shown in ways be refinished without trouble by any Fig. 4, this turn-table is made to accomplish other person upon another similar table. the same end as Dr. Matthews' deviceFor placing cells for opaque objects, its namely, the centering of the slide as to its operation is obvious; but for mounting width only. This is useful mainly when it transparent objects also it is a great con- is desired to make several cells upon the venience. The glass slips that are to be same slide from end to end, although under used should first be centered on the table, some circumstances the triangles will assist and receive a ring of ordinary water-color in refinishing badly placed specimens. This or of ink on the opposite side from that on application of the triangles, we are informed which the object is to be placed. This will by Mr. Cox, was originated by him, and serve as a guide to the proper location of described in correspondence with Dr. R. H.