Box 14, Folder 3: Coal 1861

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The thickness in the center is not more than one-eighth of an inch, and at a distance of three or four inches from the center is less than half an inch: cells cylindrical in the middle and contracted both above and below, the walls of the cavities, often showing transverse striae, which appear like the remains of septa. The distance of the cells from each other is variable, those near the center being closer together, though, in receding from the center, there are at intervals intercalated rows of cells, which take the same direction, and give the cells a closer arrangement towards the margin than in the intermediate space before the intercalation of the additional rows. The apertures both above and below are essentially rhomboidal; but in well preserved surfaces there are remains of rays, which, however, are rarely observed;* and I have not seen them on opposite sides of the same specimen.

The various stages of decomposition, and degrees of preservation, present a great variety of surface aspect. In some conditions, there is visible a distinct groove, extending along the surface from one cell to the next, across the curving interspaces. I have not observed in any of these specimens evidences of the connecting stolous shown by Mr. Salter, (loc. cit.)

Geological Formation and Locality.---In the Galena limestone of Wisconsin, Northern Illinois, and the eastern part of Iowa, this fossil is everywhere present, and is the most marked and characteristic form in the rock. It likewise occurs sometimes in positions where the Galena limestone is extremely thin, or not recognized as a distinct member of the group.

In the study of this species, which will be fully illustrated in the forthcoming report, I have been furnished with specimens by Messrs. I. A. Lapham, of Milwaukee, and J. H. Adams, of Lancaster; Prof. Nason, of Beloit, Wisconsin, and Mr. T. D. Robertson, of Rockford, Illinois.

RECEPTACULITES (Selenoides) IOWENSIS.

Selenoides Iowensis, Owen, Report on the Geology of Wisconsin, Iowa and Minnesota, p. 587, pl. 2, fig. 13.

Description.---Body discoid, convex below with a broad central attachment; upper side depressed in the centre, with an elevated and rounded border; cells arranged in radiating curved lines from the centre to the periphery, and which continue on the sides and lower surface; the cells are cylindrical

*This feature is very clearly set forth in a specimen from the collection of I. A. Lapham, Esq

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within and contracted below the aperture. Surface reticulate in appearance, the cell openings communicating by a groove across the division, and between these are elevated interrupted, both ridges and grooves arranged in concentric lines crossing the cell divisions. The outline of the aperture or cell is rhomboidal, and in the centre of the bottom is a circular opening communicating with the cylindrical tube below.

When the surface is worn, it presents a series of round perforations, which are proportionally larger than they appear in unworn specimens simply from showing the diameter of the cell below the contraction. Transverse diameter three-fourths of an inch to two inches, and greatest vertical diameter rarely an inch. This species is far less common than R. Oweni.

Geological Formation and Locality.---It occurs in the Galena limestone at Platteville, Wisconsin, Dubuque, Iowa, Galena and Rockford, Illinois.

RECEPTACULITES FUNGOSU---HALL.

Description.---Body very broadly subturbinate or fungiform; rounded and very convex below, except the broad base of attachment; upper surface deeply concave in the center, convex towards the margin, and curving abruptly at the sides. Cells small, cylindrical, little contracted at the aperture, arranged in radiating curved lines from the center to the center to the periphery and continuing over the sides and base in the same direction. The central cells are vertical, but on approaching the periphery they are curved upwards and inwards; the lateral cells are directed horizontally and gradually turning downwards are again vertical, opening in the opposite direction from those of the center above.

Surface appearing reticulate from the concentric grooves which connect the cells upon the surface, and the parallel concentric ridges; while these are crossed below by the double series of diverging curved lines.

To conceive of the form of this species, one may fancy an expanded form of R. Oweni to be bent abruptly over at an inch or two from the center, and the margins drawn together below, forming a base of attachment.

The greatest diameter of this species, in the specimens examined, is about three inches; and the greatest elevation from the center of the base to the summit, is one and threefourths to two inches; the depth of the central cavity below the plane of the summit being about half an inch. The length of the cells in the thickest lateral portions of the body, is about three-fourths of an inch.

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This species if less common than either the R. Oweni or R. Iowensis. I have received, through Prof. Whitney from Capt. Beebe, of Galena, a very fine specimen for illustration, and other from Mr. Robertson, of Rockford, Illinois.

RECEPTACULITES GLOBULAR^IS.---HALL.

Description.---Body globose or sub-globose, with and irregular base of attachment; transverse diameter usually greater than the vertical diameter; summit a little depressed; cells arranged in radiating curved lines, the apertures rhomboidal and transversely elongated; the concentric groove and raised ridges between, strongly marked.

This species is readily distinguished by its small globose form, which is usually not more than three-fourths of an inch in diameter. It is more rare than either of the others, though I am informed by Prof. Daniels, that more than twenty specimens were obtained at a single locality in Wisconsin. About twenty years since, I received a specimen of this species from Mr. Thorp, of Mount Morris, Illinois, and have seen others in Galena and in the collection of Prof. Daniels.

Geological Formation and Locality.---In the Galena limestone of the lead region of Wisconsin, Iowa and Illinois.

RECEPTACULITES INFUNDIBULU^S---HALL.

Description.---Entire form of body unknown. The centre is a influndibuliform cavity, having a depth of one and a half inches with the same diameter of the summit; cells arranged in radiating curved lines; the lines of cell wall in one direction apparently curving very little, while the other seems to have a greater curve; cell apparatus quadrangular and nearly square within the central area, beyond this they are undetermined.

This species is described from some fragments in the limestone of Racine, from the collection of T. J. Hale. The geological horizon is that of the Niagara group, of New York.

RECEPTACULITES HEMISPHERICU^S---HALL.

Description.---Body hemispheric, convex above, the centre not depressed. Cells arranged in radiating curved lines, which cross each other as in the other species of the genus. Cell apertures sharply defined, rhomboidal, opening by a round contracted orifice into the cylindrical tubes below.

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The organic centre from which the cells radiate (in two specimens) is elevated, and does not quite correspond with the centre of the mass. The central cells are very minute, those near the margin having a diameter five or six times as great.

This species has nearly the same diameter as R. iowensis, but the cells are proportionally large, and the rhomboidal apertures more sharply defined, while the centre is not broadly depressed as in that one; but widely and sometimes almost hemispherically convex, with a slight depression on one side of the organic centre.

Geolocial formation and locality. In the limestone of Racine of the horizon of the Niagara limestone of New York.

Collector. T. J. Hale.

GRAPTOLITIDEAE of the Lower Silurian rocks of Wisconsin.

GRAPTOLITHUS (Diplograptus) PEOSTA, HALL.

Description. Stipe (simple?) robust, rounded on the surface, with section broad-oval; very gradually widening from base, having a width of about eight hundredths of an inch: cellules narrow-elongate, about twenty-six in the space of an inch: length about three and a half times the width of the cell, the free portion being about one-third the length; inclined to the axis at an angle of about 35 degrees; extremities of the cells truncate, the apertures somewhat quadrangular and rounded on the sides. Cell partitions strong and well defined, reaching nearly to the centre of the stipe in its lower part, leaving a very narrow space for the common body, which becomes wider above. Surface transversely striated or wrinkled.

Geological formation and locality. In the shales of the Hudson River group in Wisconsin, Iowa and Illinois.

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a substance unfavorable to the preservation of the cellules or of the finer markings of the surface. In the form and proportions of the cellules and the greater proportional width of the connecting filaments, this species differs from any of those described. Geological formation and locality. In the Trenton limestone of the Fox river, near Appleton, Wisconsin. I am indebted to Prof. R. Z. Mason, of the Appleton University, for the specimen. Near the base of the Trenton limestone at Platteville and other localities, there are some slaty layers completely charged with fragments of organic bodies which have the appearance, color and texture of the Graptolidae. In 1860 I collected from this locality numerous specimens of these shales, and I am also indebted to Mr. J. D. Whitney (lately of the Wisconsin Survey, and now Geologist of California) for a piece of limestone from the same neighbourhood, containing some of thes forms in a more complete condition. Since that period, large numbers of speciments have been collected, showing an abundance of these fragments, quite unprecedented in any locality of Graptolites, which I have examined. Many of these fragments are long and slender, and have evidently been floated and macerated before being imbedded. Some of them are twisted, together, either from their natural relations, or what appears more probably, by the action ofthe waves before these forms were finally thrown down upon the muddy bottom. A few fragments of Trilobites and shells, with valves of Leperditia, occur in the same association. Notwithstanding this abundance of fragments, I have thus far been unable to make out more than a single form in a condition to be satisfactorily described. This form is generally distinct from any heretofore described, so far as I am aware. It consists of long principal or central stipe, with diverging branches, closely arranged and often recurved. The stipes, so far as observed, are simple and linear, and the branches are simple and linear, terminating in a thickened lanceolate extremity. The main stipe is distinctly marked by round or oval spots, representing the cellules; the branches are striated, and with sometimes some obscure marks of celules. For this form I propose the Generic name of Buthograptus.

GENUS BUTHOGRAPTUS, (nov. gen)

Generic character. Frond consisting of a central stipe with closely arranged lateral branches, which are so flexuous or re-