and dark purplish brown color, when contracted giving a spotted appearance to the dorsal surface. Madreporic plate small, about half way between center and margin. Margin thickened, with an upper row of slightly prominent plates spinulated like the back; below, and forming the edge, is a row of inore prominent plates, their upper and inner portion spinulated like the back, the spinules increasing in length to the outer edge, where they are slender, elongated, crowded and divergent. Ventral plates, covering the triangular interbrachial area, prominent, with unequal, slender, acute, divergent spinules, those on the distal edge longest. Adambulacral plates with two internal acute spines, forming a longitudinal row, and four or five others in a transverse row on each plate. Color, in alcohol, dull yellow or buff, with dark brown spots, due to the papulæ. Greater radius, 12mm; lesser, 7mm; elevation at center, 7mm. Dredged near Cashe's Ledge, Gulf of Maine, in 110 fathoms, muddy bottom, in 1874, by Dr. A. S. Packard and Mr. Richard Rathbun, on the steamer "Bache," (Coll. U. S. Fish Commission). Lophaster furcifer Verrill. Solaster furcifer Duben and Koren. Taken in the Gulf of Maine, north of George's Banks, in 150 fathoms, by Dr. Packard and Mr. Caleb Cooke, on the "Bache," in 1872. This species differs so widely from Solaster in the structure of the skeleton, and the small development of the disk, as to require the establishment of a new genus for this type. It is specially distinguished by the highly developed skeleton of the under side; differentiated marginal plates; and prominently reticulated dorsal plates. Pedicellaster typicus Sars. This species was dredged in the Gulf of St. Lawrence, in 1872, by Mr. J. F. Whiteaves, who sent me specimens for examination. Asterias stellionura Perrier. This large and remarkable species, previously known only from Iceland and Greenland, was dredged by our party, on the steamer Speedwell, in 1877, at several localities off Nova Scotia, in large numbers. It was especially abundant off Cape Sable, in eighty-eight to ninety-two fathoms, fine compact sand; and off Halifax in one hundred fathoms, sandy mud, where it was associated with Astrogonium granulare, Hippasteria phrygiana, Archaster Parelii, Archaster arcticus, Antedon Sarsii, and many other arctic species. This species can be distinguished from all others of our coast by the five, very long, angular arms, with long slender spines, which are surrounded at base by large dense wreaths of crossed pedicellariæ. In life these clusters of pedicellariæ are supported on soft extensible processes, which project beyond the ends of the spines of the lower surface, giving it a very peculiar appearance. Some of the specimens were two feet in diameter. The color was usually bright red above, yellowish below; some specimens varied to orange-red, and others to purplish or brownish red, above. Ophiacantha anomala G. O. Sars, Vidensk.-Selsk. Forhandl., 1871. A handsome species, having six arms, and of a bright salmoncolor when living. A single specimen was dredged by us in the Gulf of Maine, 140 miles east of Cape Ann, in 112 fathoms, sand and gravel, in 1877. With this was associated another beautiful salmon-colored species (?Amphiura Otteri Ljung.) with five long slender arms. Ophioscolex glacialis also occurred at the same locality. Both the latter had, however, been taken by our parties in previous years. ART. XXI.-Positions of the Comet discovered by Mr. Lewis Swift; by C. H. F. PETERS. (From a letter to the Editors, dated Litchfield Observatory of Hamilton College, Clinton, N. Y., July 6, 1878.) OF the comet found by Mr. Lewis Swift of Rochester on July 6, the following positions were here obtained: h. m. 8. 12 33 43 17 34 19.87 ♪ Comet. +16°57' 31.5" 6 comp. 10 4 8 July 7, July 10, 13 5 53 July 19, 10 27 58 July 23, 9 42 12 The approximate parabolic elements herefrom derived are: (Epoch) Time of Perihelion passage, July 20·753 Berlin m. t. 279°52'06 } M. Eq. 1878.0. Much labor would be saved to astronomers, if comet-hunters like Mr. Swift, would indicate the position of a new discovery with a little more accuracy. For obtaining it with only a few minutes' error, nothing else is needed but a common watch in connection with the field of the telescope used as a ringmicrometer. AM. JOUR. SCI.-THIRD SERIES, VOL. XVI, No. 93.–SEPT., 1878. ART. XXII.-The Waverly Group in Central Ohio; by L. E. HICKS, Professor of Natural Sciences in Denison University. In this paper I propose to enumerate and describe the strata lying between the Huron Shales (Devonian) and the base of the Coal Measures, and to consider briefly their stratigraphical relations. I shall use names derived from localities in Licking and Delaware Counties-not that I wish to add to the already profuse nomenclature of this group, but as a matter of necessity until the application of the names proposed by other geologists has been definitely settled. The section contains five well defined members, named below in descending order. 5. Licking Shales 4. Black Hand Conglomerate and 3. Raccoon Shales. 2. Sunbury Black Slate.. 66 1. Sunbury Calciferous Sandrock.. 90 100 The Licking Shales, No. 5, are well developed in the hills bordering Licking River from Newark to Black Hand. They lie seventy to eighty feet above the water level, forming the middle of the slope of these hills, the base being composed of the massive Black Hand Conglomerate and the upper slopes and summit of the various strata of the Coal Measures, of which the Coal Conglomerate and Massillon Sandstone produce the most conspicuous effects in the landscape. At or near the top of No. 5 there is usually a stratum of compact, fine-grained, drab sandstone, which is quarried to some extent, having a thickness of three to ten feet. Below this are friable, earthy, gray or olive shales; and at the bottom, comprising about onethird of the whole, shaly drab sandstones. These, and the compact sandstone at the top, are fossiliferous. Spirifera Carteri, Aviculopecten Winchelli, Allorisma pleuropistha, and other characteristic species of the Ohio Subcarboniferous, have been obtained from this horizon. Wherever the Coal Measures Conglomerate exists it forms the upper limit of the Licking shales, which is then well defined. In the absence of the Conglomerate the only means of determining its extent upward is the position of the compact sandstone and the presence of Subcarboniferous fossils. Frequently the sandstone is overlaid by shales differing scarcely at all from those below it. The lower limit, however, is perfectly defined by the upper surface of the next stratum, which is one of the most distinctive and well-marked of the whole group. The Black Hand Conglomerate, No. 4, is seen at its best about Hanover, though the Black Hand locality is better known, probably because the cliffs at that point are more conspicuous to the railway passenger. Only about half its thickness is seen in these cliffs. At Hanover the bottom layers (which, owing to the eastward dip, are buried out of sight at Black Hand) come into view and reveal a total thickness of eighty-five to ninety feet. It is generally a rather fine pudding-stone, the pebbles of the size of peas. Occasionally they are an inch in diameter, and, in one case, I found a quartzite bowlder six inches long and three inches thick imbedded in the sandy matrix. In some places beds many feet thick are merely coarse sandstone, but the partings are pebbly. The prevailing color is light yellow or buff; sometimes nearly white, again brick-red. This stratum is highly ferruginous, but less so than the Coal Conglomerate, the upper layers of which are sometimes a siliceous iron ore. It also contains more earthy matter and less pure silica than the Coal Conglomerate. These characters, together with the presence of fossil nuts (Cardiocarpon, Trigonocarpon, etc.) in the upper, and their absence, so far as yet observed, in the lower, might serve to distinguish these conglomerates if they were in contact, instead of being separated by the Licking Shales. No. 4 is evidently a shore deposit, and it exhibits the typical structure of a sea beach better than any other rock with which I am familiar. There is, in the first place, the regular beach slope of four to ten degrees, which for six miles along the Licking River is tolerably constant in direction, viz: N. 10° to 45° E. Then there are subordinate lines of oblique lamination dipping in all directions. These last do not, however, interfere with quarrying. The rock splits along the beach slope as if that was the dip, and comes out in regular blocks of any size desired. In durability it is unsurpassed, while it is not destitute of beauty as a building stone. Its great value for canal locks, bridge abutments, foundations, etc., has long been recognized; and its capabilities for massive and elegant superstructures have been shown in the erection of the cathedral at Columbus. Like almost all Conglomerates, No. 4 thins and disappears, or passes into fine sediments when traced far from its typical exposures. Black Hand is near the east line of Licking County. The Conglomerate appears in full force for seven or eight miles, to some distance west of Clay Lick station on the Baltimore and Ohio Railroad. Thence through the center of the county its horizon is occupied by an entirely different set of beds, of which only one, and that thin, bears any resemblance to the rock at Black Hand. These beds are character istic and important enough to merit a full description and a separate name. They are well exposed at Granville, and we may for convenience designate them as the Granville beds, remembering that they are only a local modification of No. 4, or the next highest member of the Waverly group. Following is the section of these beds in descending order: No. 4d. Coarse sandstone and conglomerate... 3 to 18 feet. 66 4c. Fucoid layer 66 7 12 46. Compact drab sandstone (argillaceous).15" 21 66 and shales 66 66 66 60 The upper member, No. 4d, thickens and grows coarse and pebbly eastward, and tapers to a knife-edge westward. Hence was at first disposed to regard it alone as the equivalent of the Black Hand conglomerate, and to suppose that the rest of the Granville beds dipped under that stratum. But careful measurements have shown that the bottom of the Granville beds near Newark is nearly the same distance below Coal I. as the bottom of the conglomerate at Black Hand; so that, if the latter is superimposed upon the former, there must be a sudden thickening of the whole series to the extent of eighty or ninety feet. The general regularity of the dip renders this highly improbable. It The Fucoid layer, No. 4c, is composed of brown, gray, and blue, earthy shales, filled with the remains of Spirophyton cauda galli. At some points these plants are so numerous that the whole rock becomes a tangled mass of sea-weeds. weathers black by the oxidation of its manganese. The upper half is more friable than the lower, and falls to pieces in being removed; the workmen in some quarries call it "soapstone." The lower half, "nigger-head," requires blasting, being quite compact in the quarry, from which it has to be "stripped" to get at the next layer, No. 4b; but it soon falls to pieces under the action of the elements and lays bare the rich treasures of its molluscan fauna, which the quarrymen call "bugs" and "butterflies." This layer is so well defined and persistent that it furnishes a reliable means of determining the dip. This has been found to be on the average twenty-one feet ten inches per mile, nearly due east. Instead of being uniform, however, this general eastward slope is broken into small waves, which correspond to the greater ones in the Appalachian mountain system, both in direction and in having their western slope steeper than the eastern. No. 4b is a fine-grained, easily-wrought sandstone, extensively quarried at Newark and Granville. The shaly sandstone below it also thickens in some places into layers suitable for quarrying, but it is not reliable. |