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��the fact lliat tbiis far all attempls at connecting auroral plietiomena direct]; with iiieteoroioglcal have failed, goes tar to sliow a coamic rather Iban a terres- trial origin for the aururn. II. A. H.

An extinct bydrold. Whether Shakspeare was the first to give eipres- sinn to the idea of 'Seriuons in stones,' the writer of this notice is not scholarly enough to answer. Strongly impressed by many demonstrations of lis Irutb, It is In no spirit of detraction that he ventures the opinion that the inspired bani could not have appreciateU the sigiilBcance of his dectaralion, if we take Into consideration what these sermons have since revealed to us of the past history of the world. The rocka have proved to be volumes of the moat convincing sermons, and every pebble has a story that may be read. Such a pebble, the subject of the present communication, was sent lo the writer by a greatly esteemed friend, the well-known natiiralist and philologist. Prof, Samuel S. Haldeinan, shortly before his death. It was picked up in Lebanon coun- ty, Penu., but exactly at what locality I failed to liicguire. It is an Irregular rectangular piece of quartiite, about an Inch and a quarter In two diameurs, and half an Inch in the third diameter. It has several conchoidal fractures, is waler-rolled, with ruundeil edges, and smooth. It la dirty white, opaque, homopeneous, and of flinty texture. Embedded In it, scattered here and there, are laen several dozen little fos- sils, all of the same character, and worn level with the smooth surfaces of the pebble. Most of the fossils have the form of a narrow ellipse with acute extremities, or hare the shape of a sec- tion of a double convex lens. Where they cross the edges of the pebble, Ihey exhibit the same form of outline on the contiguous surfaces; bo that, If isolated, they would appear lo be actually lenticular in form. They are composed of smoky-colored quartzite, cross-barred with while, and contrast conspicuously with their matrix. My first impression, on seeing the pebble, was, that the fossils were rhixopods, related to the nummulites; but an in- spection with a lens indicated them n±Lu%ai,Jn probably to be bydrolds related to the pnnuEVA, graptolltes, and especially to Phytlo- graptus. The lenticular sections of the fossils gener- ally range from four to nine rolllimetres in length by one to one and three-eighths millimetres In thickness at the middle. As represented in the accompanying figure, the white bars crossing the short diameter of the lenticular Becliuns are produced by what appear to be two TOWS of cells, with their bottoms applied to- gether inwardly, and separated by a median, slightly undulating line. Hsny of the cells are flask-shaped, with the neck directed outward, and reaching the con- vex surface of the fossil. In others the neck is vari- ably shorter, and in >ome appears to be absent, the difference apparently being dependent on sections of the cells at different levels. In the specimen figured, theheaked cells appear somewhat curved or retort-like, but in other specimens they are stralgtal. The body of the cells mostly exhibits a nucleus of smoky hue, while the walls of the cells are white, though not sharply defined from the nucleus. The appearance seems to be due to the Interior of the cells being occupied by

��a more translucent deposit of silex. In several of the fossils like the one figured, the number of cells in each row is about two dozen. The lenticular sec- tions of the fossils are not all equally symmetrical with the one figured, some bulging more on one side than the other, and a few being lliicker towards one pole tlian the other, and less acute at the end. Two specimens, of which one is eleven millimetres long, are slightly constricted near the middle, and look like conjoined pairs. Another specimen, unlike the others, extends across the pebble for about eighleeti millimetres, is of nearly uniform width tliroughout. and Is broken near the middle. One eitrenif ly curves laterally, and ends In an obtusely rounded manner: the other extremity extends obliquely in an opposite direction, tapers a short distance, and Is then pro- longed to a broken end.

From the well-known graptolltes of the Silurian rocks, our fc)8si! differs especially In t!i« cells being embedded in a common basis or matrix, In this respect resembling such polyxoa as Criatatella in com- parison with Plumatelia. The age of the fossil I am unable to read In the pebble, though doubtless others may be able to do so. In Lebanon county the pre- vailing rocks are of lower Silurian age; and It Is prob- able the pebble pertains lo one of these, thoi^h it may have travelled from another source. The char- acter of the fossil appears to be different from any previously indicated; and I would propose to name it Haldeman* primaeva, in memory of the one who called our attention to this Interesting representative of Ihebydroids. Josei-h Leidt.

PboHphatic rocka of Florida.

In my ' Report on cotton-production In Florida,' vol. vi. of the quarto series of census reports, p. 14 (194), there Is an analysis, by Dr. G. W. Hawes, of a build- ing-stone from Hawthorne, Alachua county. This rock contains 10.03% of phosphoric acid: and it was considered as of eocene or oUgoceneage. like the rest of the limestone of the peninsula.

During the past winter, Mr. L. C. Johnson of the U. S. geological survey has been collecting in Flor- ida, and has made a very important discovery. Be finds that the building or chimney rock in several o(

��phosphatic. Specimens sent to me for examination by Mr. Johnson, from Suwannee, Levy, Alachua, and Marlon counties, are strongly phosphatic, varying in content of phosphoric acid from five to ten per cent. The material wltich contains most phosphoric acid U a porous, soft rock, consisting In the main of groins of quartz, with oecasionally a little carbnnate of lime, but seldom very much. In some of the specimens, especially those from near Waldo, Ihe soft friable rock contains small nodular masses of nearly pure phosphate of lime disseminated Ibro.ugh IL The largest oftbese nodules is sometwo inches in diameter.

By the discovery of a highly fwsilifcrous bed near Waldo, Mr. Johnson lias been able to fix the age of these phosphatic rocks as mlocenc or later; and this view is confirmed by the specimens from Rock Spring In Orange county, collected by nie lu 1880, which Professor Angelo Heilprin determined from Ihe fos- sils to be miocene. I have recently tested all these specimens, and find them, without exception, highly phosphatic.

From these facts, and others presented in the sub- joined letter of Mr. Johnson, it appears that the

deposits of miocene age are generally spread o ' "

Florida peninsula. It indeed they arc - sive with those of the oligocene.

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