May 15, 1885.] 



SCIENCE 



395 



the fact that thus far all attempts at connecting 

 auroral phenomena directly with meteorological have 

 failed, goes far to show a cosmic rather than a terres- 

 trial origin for the aurora. H. A. H. 



An extinct hydro-id. 



Whether Shakspeare was the first to give expres- 

 sion to the idea of 'Sermons in stones,' the writer 

 of this notice is not scholarly enough to answer. 

 Strongly impressed by many demonstrations of its 

 truth, it is in no spirit of detraction that he ventures 

 the opinion that the inspired bard could not have 

 appreciated the significance of his declaration, if we 

 take into consideration what these sermons have 

 since revealed to us of the past history of the world. 

 The rocks have proved to be volumes of the most 

 convincing sermons, and every pebble has a story 

 that may be read. Such a pebble, the subject of the 

 present communication, was sent to the writer by a 

 greatly esteemed friend, the well-known naturalist 

 and philologist, Prof. Samuel S. Haldeman, shortly 

 before his death. It was picked up in Lebanon coun- 

 ty, Penn., but exactly at what locality 

 I failed to inquire. It is an irregular 

 rectangular piece of quartzite, about an 

 inch and a quarter in two diameters, 

 and half an inch in the third diameter. 

 It has several conchoidal fractures, is 

 water-rolled, with rounded edges, and 

 smooth. It is dirty white, opaque, 

 homogeneous, and of flinty texture. 

 Embedded in it, scattered here and 

 there, are seen 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 have the shape of a sec- 

 tion of a double convex lens. Where 

 they cross the edges of the pebble, they 

 exhibit the same form of outline on 

 the contiguous surfaces; so that, if 

 isolated, they would appear to be 

 actually lenticular in form. They are 

 composed of smoky-colored quartzite, 

 cross-barred with white, and contrast 

 conspicuously with their matrix. My 

 first impression, on seeing the pebble, 

 was, that the fossils were rhizopods, 

 related to the nummulites; but an in- 

 spection with a lens indicated them haldemana 

 probably to be hydroids related to the primaeva. 

 graptolites, and especially to Phyllo- 

 graptus. The lenticular sections of the fossils gener- 

 ally range from four to nine millimetres 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 sections are produced by what appear to 

 be two rows of cells, with their bottoms applied to- 

 gether inwardly, and separated by a median, slightly 

 undulating line. Many 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 some appears to be absent, the 

 difference apparently being dependent on sections of 

 the cells at different levels. In the specimen figured, 

 the beaked cells appear somewhat curved or retort-like, 

 but in other specimens they are straight. 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 thicker towards one 

 pole than 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 eighteen 

 millimetres, is of nearly uniform width throughout, 

 and is broken near the middle. One extremity 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. 



Prom the well-known graptolites of the Silurian 

 rocks, our fossil differs especially in the cells being 

 embedded in a common basis or matrix, in this 

 respect resembling such polyzoa as Cristatella in com- 

 parison with Plumatella. 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 to one of these, though 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 

 Haldemana primaeva, in memory of the one who 

 called our attention to this interesting representative 

 of the hydroids. Joseph Leidy. 



Phosphatic rocks 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 16.02% of phosphoric acid; and it was 

 considered as of eocene or oligocene age, 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. He 

 finds that the building or chimney rock in several of 

 the counties of the state, and probably wherever it is 

 found, like that occurring at Hawthorne, is generally 

 phosphatic. Specimens sent to me for examination 

 by Mr. Johnson, from Suwannee, Levy, Alachua, and 

 Marion counties, are strongly phosphatic, varying in 

 content of phosphoric acid from five to ten per cent. 

 The material which contains most phosphoric acid is 

 a porous, soft rock, consisting in the main of grains 

 of quartz, with occasionally a little carbonate of lime, 

 but seldom very much. In some of the specimens, 

 especially those from near Waldo, the soft friable 

 rock contains small nodular masses of nearly pure 

 phosphate of lime disseminated through it. The 

 largest of these nodules is some two inches in diameter. 



By the discovery of a highly fossiliferous bed near 

 Waldo, Mr. Johnson has been able to fix the age of 

 these phosphatic rocks as miocene or later ; and this 

 view is confirmed by the specimens from Eock Spring 

 in Orange county, collected by me in 1880, which 

 Professor Angelo Heilprin determined from the 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 over the 

 Florida peninsula, if indeed they are not co-exten- 

 sive with those of the oligocene. 



