their characteristic covering, all clearly owing their origin to one common and simple cause.* The series might, perhaps, be extended even farther, so as to include the structure known as "Cone-in-Cone," which, according to the investigations of the author, is probably due to the action of pressure on concretionary structure when in process of formation. Intermediate forms between Stylolites and Cone-in-Cone had been observed by the author, and also some other similar structures, the origin of which he hoped to discuss in a future paper.

Whenever displacement of any kind takes place in strata, the adjoining surfaces that thus move past each other do not usually again firmly unite; and hence various substances are often introduced by infiltration into the intervening spaces. In this way the surfaces of Stylolites and the enclosing rock not unfrequently become covered with oxides of iron, either in the form of deudrites, or of a uniform coating. Carbonate of lime, or of lime and magnesia, sulphate of lime, and of strontia when introduced, in this manner often crystallize in the grooves on the sides of the columns or sutures, thus apparently forming fibrous crystals; and consequently, these have, perhaps not unnaturally, been regarded as essential elements in the formation of Stylolites by those who had made but a limited study of the subject. Hence the various crystallization theories that have been proposed, each regarding the particular substance detected as the cause of the structure. The dark coating on columns and in sutures, which has been considered bitumen by several authorities, will generally be found, on examination, to be either a portion of the argillaceous layer, separated by the Stylolites when forming, or, as in the case of Slickensides, merely a portion of the rock, finely divided and compressed. The dark color may, of course, be heightened by the subsequent infiltration of organic substances, but the coating itself is in nearly all cases essentially inorganic.

The localities of Stylolites in this country are very numerous, and allusion has already been made to some of the more important. The most interesting one known to the author is in the Clinton limestone at Lockport, N. Y., where nearly all the perfect columns are crowned with fossils. The best exposure at this locality, now accessible, is at Cady's quarry, a few rods below the railroad bridge over the canal;

* A suite of specimens, from various localities in this country and in Europe, illustrating such a series, was exhibited by the author.

but the terrace of limestone on which this part of the city is built contains throughout its whole extent fine illustrations of this structure. Apparently the same beds are exposed in the railroad cutting on the Niagara River above Lewiston, nearly twenty miles distant, as layers having essentially the same position, and containing similar Stylolites, have been observed by the author there and at various points where the Clinton crops out along the "Mountain" ridge; and Dr. A. M. Leonard, of Lockport, has since discovered other intermediate localities, which render the connection more than probable, thus indicating a very large extent of surface, over which the same peculiar causes were in operation at the same time.

Besides the localities already referred to, many others of interest occur in the Silurian, Devonian, and Carboniferous, and more rarely in the Triassic. In New York and Canada the Niagara and Corniferous limestones often contain imperfect Stylolites in abundance, while in the West fine illustrations of the structure have been found in the subcarboniferous. Special localities may readily be ascertained by consulting the various State Geological Reports.

One of the most interesting localities of Stylolites in Europe is that already mentioned in the Muschelkalk at Rüdersdorf, near Berlin, where this structure is developed in great perfection. Nearly all the separate columns are capped with fossils, and a great variety may easily be obtained. During a visit to the locality in 1864, the author collected more than fifty characteristic columns, each having an organic covering, and among these ten species of fossils were represented. The Muschelkalk and Zechstein in other parts of North Germany also frequently contain Stylolites in abundance. In Würtemberg, columns with a black coating are common in the Muschelkalk near Friedrichshall, and at Rottweil Stylolites are occasionally found having on their summit a fossil crab.* Various localities of Stylolites have been observed in France, one of the most important of which is in the Jura near Dijon, where columns a foot in length were noticed by M. d'Aoust.† In Great Britain this structure appears to have attracted very little attention, and no localities of particular interest have been described. In the subcarboniferous limestones of Ireland the author had observed the more common varieties of Stylolites at several places, but the structure was nowhere well developed.

*Von Alberti. Überblick über die Trias, p. 15.

† Bulletin Soc. Geol. de la France, Vol. III. p. 327.

II. PALEONTOLOGY.

1. ON SOME FOSSIL REPTILES AND FISHES, FROM THE CARBONIFEROUS STRATA OF OHIO, KENTUCKY, AND ILLINOIS. By J. S. NEWBERRY, of New York, N. Y.

THE specimens exhibited and described in this communication consisted of reptiles and fish from the cannel stratum underlying the main coal seam at Linton, Ohio, of fishes from the coal measures of Illinois, collected by the State Geologist, and of a group of fishes collected by Dr. Patterson from a stratum of bituminous shale, lying in the Waverley group, one hundred and twenty-five feet above its base, at Vanceburg, Kentucky. Of these, the first series included Raniceps Lyellii, Wyman, with several as yet undescribed reptiles, some of which apparently belong to Prof. Huxley's new genera, Ophioderpeton and Urocordylus. Associated with these were some twenty species of fossil fishes, most of which have been described by Dr. Newberry, but were now represented by new and more perfect specimens. Among these were eight species of Eurylepis, a genus created by Dr. Newberry to receive a group of small lepidoids, allied to Palæoniscus, but distinguished by the scales of the sides which are much higher than long. The scales on several of these species are very highly ornamented. The specimens exhibited were preserved in cannel coal, and covered with a film of sulphide of iron, by which they were brilliantly gilded. With these were two species of Cœlacanthus, some of the specimens of which showed that the fishes of this genus were furnished with a supplemental caudal fin, as in Undina. This Dr. Newberry stated was an interesting fact confirmatory of Prof. Huxley's view of the relations of Undina, Macropoma, and Coelacanthus. The numerous and very complete specimens of Cœlacanthus exhibited supply much that was wanting to a perfect knowledge of the anatomy of this genus. The bones of the head are similar in form to those of Macropoma, are highly ornamented with tubercles above lines below. The jugular plates are double and long-elliptical as in Undina and Macropoma. The position and form of the fins are as in Undina, but the anterior dorsal is stronger. The fins are supported on palmated interspinous bones, similar, in a general way, to those of the other genera of the family. The paired fins are slightly lobed. The supple

mental has been referred to. The scales are ornamented with curved and converging raised lines. In many specimens the earbones (otolites) are distinctly visible. Besides the fishes found at Linton already enumerated, there were scales and teeth of Rhizodus, two species, at least, one of which (R. angustus) has teeth of two forms, one large, flattened, and double-edged, the other smaller, more numerous, slender, sheathed, and conical, with a circular section throughout; two species of Diplodus, consisting of bony base and enamelled crown, the latter distinctly and beautifully serrated, so that there can scarcely be a question that they were teeth, and not, as claimed by Mr. Atthey, of Newcastle, England, dermal tubercles. In the Linton fauna is one species of Palæoniscus (P. scutigerus. N.); one of Pygopterus; one of Megalichthys, represented by scales; and numerous spines of placoid fishes of the genera Compsacanthus and Pleuracanthus.

The fish remains from Illinois consisted of a splendid specimen of Edestus vorax (Leidy), from the coal at Belleville, opposite St. Louis, and of several individuals of a new species of Platysomus from the concretions of iron ore at Mazon Creek. The Edestus was said by Dr. Newberry to have been described as a jaw, but the specimen exbibited was much more complete than any before found, and there could scarcely be a doubt that it was the spine of a Selachian. Platysomus, he said, though common in the coal measures of England, had not been before found in America.

The fishes from the Waverley were from a new locality, and from a horizon that had furnished very few fossils of any kind, and no fishes except a Palæoniscus (P. Brainerdi) found in Northern Ohio. The specimens collected at Vanceburg by Dr. Patterson consisted of teeth of Cladodus and Orodus, with spines of Ctenacanthus, with the tail of one of these Selachians distinctly preserved. This, Dr. Newberry said, was a great rarity, as the soft, and even the cartilaginous parts of plagiostomous fishes had usually disappeared, the teeth, spines, and dermal tubercles, the only bony parts, remaining. The only similar cases, of which he had any knowledge, was the discovery of the tail and fins of Chondrosteus in the Lias of Lyme Regis, England, and the preservation of Thyalina in the Solenhofen slate. The specimen shown was greatly older, being from the base of the carboniferous, and was the only figure that Nature had given us of the external form of these ancient sharks. This tail was very heterocercal, had the from of the 19

VOL. XVI.

caudal fins of some living sharks, and indicated a fish of seven or eight feet in length. In the specimen exhibited the vertebral column had entirely disappeared, but the impressions of the spinous bones were distinctly visible, those of the lower lobe of the tail being ossified throughout. Dr. Newberry said that he hoped to gather data from this collection for uniting teeth and spines, which, though described under different names, were parts of one fish,

2. ON SOME REMARKABLE FOSSIL FISHES, DISCOVERED BY REV. H. HERZER, IN THE BLACK SHALE (DEVONIAN) AT DELAWARE, OHIO. By J. S. NEWBERRY, of New York, N. Y.

DR. NEWBERRY exhibited to the section different portions of the head of a gigantic fish, to which he had given the name of Dinichthys Herzeri, and which, he said, from its size and structure, deserved the same distinction among fishes that Dinotherium and Dinornis enjoy among mammals and birds. Most of the bones obtained as yet belonged to the head, which was over three feet long, by one and a half broad, and wonderfully strong and massive. All parts of the head had been procured, and many different individuals were represented in the collections made by Mr. Herzer. The cranium was composed of a number of plates firmly anchylosed together and strengthened near the occiput by internal ribs, or ridges, nearly as large as one's arm. The external surface was covered with a very fine vermicular ornamentation. The anatomical structure was more wonderful than the size, and was such as to separate this quite widely from any fishes known, living or fossil. The most marked peculiarity was in the structure of the jaws and teeth, both as regards the form and texture. The form of the jaws will be best understood by the following figures:

Mandible one-eighth natural size.