Alethopteris, with Callipteris Sullivanti, are said to characterize Coal No. 2. Sphenopteris is considered "peculiar to the lower Coal-measures.' "As representative of the higher coal strata of Illinois, there is no particular species to quote." "In the anthracite region of Pennsylvania, the highest strata are recognized by the presence of Pecopteris arborescens, which has not been as yet positively discovered in Illinois. In Europe it ascends to

the Permian."

** *

As the Lycopodia decreased in numbers and in size, they were "proportionally replaced by ferns."

As

The relation of the Coal-measures of Illinois to those of Pennsylvania, Rhode Island and Nova Scotia is indicated by the identity of numerous species of ferns. Of the common species of our eastern coal-fields, only one has not yet been found in Illinois. regards the relation of these beds to the coals of Europe "no genus of our coal flora, except perhaps Calamites, can be considered as represented on both continents by species all identical or closely allied. As these points of difference, like those of affinity, have been observed from the beginning of the researches on the coal flora, and have not varied much in comparative quantity, they appear to fully corroborate the statement that, at the Carboniferous epoch, the flora which formed the constituents of the coal was, in Europe and in the United States, as different and at the same time as relatively alike, as is now the flora of the peat bogs of the two continents."

F. H. B.

2. On some points connected with the Cretaceous and Tertiary of North Carolina; by T. A. CONRAD. (From a letter to J. D. Dana, dated Greeville, Pitt Co., North Carolina.)-I have been labelling the collection of fossils at Raleigh, and am now here exploring the marl pits and bank of Tar river. I have heard so much of the mixture of Miocene and Cretaceous fossils, that I was delighted to have an opportunity to see the beds where it occurs, I thought you would like to have a sketch of them. They run 'from three to five feet deep, and indicate the proximity of a Cretaceous shore, not an Eocene one, for we find only Greensand fossils, and they are extremely rare. The marl is fine sand, mixed with gravel and a profusion of broken shells, some water worn, having evidently been rolled in the surf; but among these fragments is a multitude of entire bivalves and univalves not in the least abraded. In company with Col. Yellowby of this place I was walking over a marl heap, when he picked out of the marl a horse-tooth, which I think is Leidy's E. fraternus. Lying on the top of the marl, it had evidently been thrown up from the lower part of the bed, and is black and mineralized. From the numbers which have been found in similar situations I am forced to conclude that the horse was a Miocene quadruped; and if this tooth should prove to have belonged to E. fraternus, it will fix the date of the Pea-shore clay near Philadelphia. Prof. Kerr has a new Busycon, eight inches long, which connects the two genera Busycon and Sycotypus, for it would belong to the latter if it had a distinct

canal at the sutures, but it has only a depression there. He has also a Mastodon jaw with two teeth on each side and two straight tusks projecting from the lower jaw. This, although found on top of the marl, I believe to have been a Miocene species, drifted on the marl by the rush of waters at the close of the period.

In the drift over the marl among sand and gravel on the shore of Tar river are great numbers of shark teeth, water-worn, mixed with water-worn fragments of friable granite. There is no material variation of the beds from those of New Jersey and Maryland by which a doubt of their synchronous deposition could be sustained, and a very few species are so like the recent ones that they might pass for the same. The same colossal Pectens abound as in Virginia, only the P. Madisonius so abundant in Virginia and Maryland is replaced by P. Jeffersonius and P. septenarius, five or six inches in width.

At Col. Yellowby's marl pit where digging is now in progress, I found the Miocene about three or four feet in thickness, resting on black Cretaceous sand with black gravel, and containing characteristic Ripley group fossils. It is here that a profusion of Belemnites is thrown up by the laborers, over the Miocene marl heap, and give rise to the opinion that they occur in the Miocene marl.

At Snow Hill, twenty-two miles from here in Green county, the Ripley Group is finely developed, containing closely packed specimens of the Ripley species in perfect preservation.

3. On the Earthquake at Oahu, Hawaian Islands, on Feb. 18; by Professor W. D. ALEXANDer. (From a letter to J. D. Dana, dated Oahu College, Feb. 28, 1871.)-I herewith send you some copies of our island papers containing accounts of a severe earthquake, which was experienced here on the 19th of this month. It was the severest earthquake ever experienced on the island of Oahu within the memory of man. In fact it was quite as severe here as on Hawaii, and seems to have been felt most severely at Lahaina. As I am not quite satisfied with the accounts of it published here, I will add a few facts that I have collected.

In regard to the time, Flitner's astronomical clock stopped at 10h 11m 17 P. M., Honolulu mean time, allowing for the error of the clock. In regard to the duration of the shock, Rev. G. Williamson, Dr. J. Hutchinson, Judge Hartwell and one or two others who timed it carefully, agree within a few seconds in making it 55 seconds. The general opinion here is that it lasted. about a minute, and the same was the case at Lahaina and Hilo.

In regard to the direction of the shock, the motion was chiefly vertical with a rocking movement northeast and southwest. It was compared by some to the sensation of riding a "bucking mustang" or driving a cart over a rough corduroy road. Many stone and adobie buildings were badly cracked, particularly our school house, the large stone church, the Queen's hospital, and the court house, and the northeast and southwest walls were generally most shaken. Stone fences running northwest and southeast were thrown down, while those at right angles to this direction

were not injured. Doors facing southwest were swung open, and hanging lamps were left swinging for ten or fifteen minutes in almost every instance in the same direction, viz. from northeast to southwest. Considerable crockery was broken, and heavy articles of furniture displaced. The usual roaring sound preceded this earthquake. Persons who were on board ships in the harbor report that they heard this terrible roaring sound far out at sea, and then the ships that lay farthest out were first struck and afterward those that lay at the wharves. They agree that the vessels were first drawn violently out to sea and then in the opposite direction.

Several persons of undoubted veracity insist that they saw a flash of light on Punchbowl hill the moment before the earthquake commenced. At Waialua at the north end of this island the shock was comparatively slight. At Waianae on the N. W. of this island, the earthquake was severe. Quite a landslip took place, carrying a house several rods. At Koolau, milk was thrown out of pans east and west. The schooner Annie in the channel south of Lanai was terribly shaken, and her bulwarks split amidships.

At Lahaina, as you will see by the papers, the shock was more severe than here, the ground cracked open in many places, and all the stone or adobie houses in the town were badly damaged. Rev. S. E. Bishop of Lahainaluna Seminary gives the time as 10h 15m P. M. The direction of the vibration was from south to north, or according to some from S.E. to N.W.

At Molokai the shock was severe, especially at the western end. The road up the great pali of Kalaupapa on the north side was rendered impassable.

At Wailuku, on the east side of West Maui, the earthquake was much less severe, stone walls being thrown down in some places, but no serious damage done. The time by my father's clock, which is set by the sun, was 10h 20m P. M., equivalent to about 10h 15 Honolulu mean time. At Makawao on East Maui the shock was slight. At Capt. Makee's, on the S.W. side of Haleakala, it was much less severe than at Lahaina. A train of molasses kettles was displaced, which was about the only damage done. The earthquake along the west coast of Hawaii was almost simultaneous with that experienced here, and about equal to it in severity. From Kohala I learn that the shock seemed to come from the west, that some stone walls were shaken down, but the stone church and plantation chimney remained uninjured. We hear the same story from Waimea and Kawaihae. From Kona, Mr. Parke writes, that the time of the shock was 10h 5m by his watch (which is probably within five minutes of the true time), that stone walls were thrown down, but no great damage done. At Hilo the earthquake was much lighter. According to Judge Hitchcock it took place at 10h 15m P. M., and lasted a minute.

From Kauai I hear that it was severe at Koloa on the south side of the island, but less severe and light on the north side at

Hanalei. No earthquake wave of any consequence is reported from any quarter.

The phenomena seem to me to point to a center of disturbance to the leeward of the islands, perhaps at the center of the circle of which the islands form an arc, and at a great depth. But as you see, our data are as yet very imperfect. There have been several slight shocks felt here since, on the 22d and 24th. I cannot learn that there is any unusual action going on at Kilauea or in Mokuaweoweo.

I am hoping to commence the survey of these islands next May. 4. Note on Trimerella acuminata; by E. BILLINGS. (Communicated by the author).-The genus Trimerella was founded by me on two species, T. grandis and T. acuminata; but of the latter I had only the rostral half of the ventral valve of a small specimen. I therefore named it provisionally and stated that it differed "from T. grandis in having the spiral extremity much more pointed, and the longitudinal septa running all the way to the beak." (The septa here alluded to and the walls between the tubes mentioned below). Within the last few days Mr. T. C. Weston, of our survey, discovered several new specimens, among which are two exhibiting the casts of both valves in connection. It then immediately became evident that several separate dorsal valves in our collection belonged to the same species. I have, therefore, now abundant material to illustrate the species, which I shall do soon, but in the meantime propose to notice its leading characters briefly.

The ventral valve, in young specimens, is somewhat straight along the median line, but becomes more and more arched as the size increases. It is ovate, rounded in front, widest a little in advance of the mid-length, thence tapering with nearly straight sides to the beak which is narrowly rounded,-almost acute. the substance of the shell there are two large tubes, which extend from about the mid-length to the beak. These are joined in the beak by two others, one on each side. All of these tubes are open anteriorly, but closed at their terminations in the beak. The area is large, concave and transversely striated. The dorsal valve is much shorter than the ventral, more convex and has its beak very strongly incurved. It has two tubes which extend nearly to the apex of the beak. The shell is marked with coarse concentric accretion ridges of growth. Length of the largest specimen 3 inches, width 3 inches. The above is sufficient to show that this species is quite distinct from T. grandis. If a section were to be made across the beak of a perfect shell of T. acuminata, it would show four perforations arranged in a curve, exactly as in the similar section of the Swedish species figured by Dr. Lindström. But if the beak of T. grandis were to be cut across, it would show only two orifices, and they would be the homologues of the two lateral perforations in the section of T. acuminata, because in T. grandis the two central tubes do not extend into the beak, but terminate before they reach it.

Montreal, May 5th, 1871.

5. Note on the discovery of the opercula of Hyolithes in New York; by S. W. FORD. (Communicated by the author).-Several weeks ago, being in Montreal, I showed Mr. Billings, Paleontologist of the Geological Survey of Canada, a small collection of fossils that I had made in the Primordial rocks near this place. He pointed out to me, that among them there were the opercula of two species of Hyolithes. One is a minute circular species with four pairs of lateral muscular impressions, and two smaller, dorsal, all radiating from a point near one side. The other species is larger and like a Discina on the outside. Mr. B. showed me several specimens of the smaller species, that had been collected by Mr. T. C. Weston of the Canadian Survey last summer, in rocks of the same age below Quebec. I am informed that this is the first discovery of the opercula of Hyolithes yet made on this continent. I have made some observations on the rocks of this vicinity, and collected a number of species of fossils, of which I hope to give an account at an early date.

Troy, May 8th, 1871.

6. Note on a new and gigantic Species of Pterodactyle; by O. C. MARSH. In addition to the Cretaceous fossils described pp. 447-453, the Yale College party obtained several specimens which indicate a huge flying reptile, apparently of the genus Pterodactylus. The remains belonged to two or more individuals. They are fragmentary, but some of them are quite characteristic. The distal ends of two long bones, similar in form to the tibia of a bird, are evidently portions of the peculiar metacarpal of the wing-finger. One of these, which retains the lower part of the shaft, resembles in its proportions the corresponding bone in Pterodactylus Suevicus. The condyles are well developed, and have a sweep of two thirds of a circle. They appear to have been originally somewhat oblique. In size and general form, they are not unlike those of the specimen figured by Owen in his Memoir on Cretaceous Reptiles, 1851 (Sup. I, Pl. IV, fig. 9-11), but there was apparently no longitudinal elevation between them. The shaft, where broken, is subtrihedral, with the posterior face concave. The bones are light, with thin compact walls. The long bones are pneumatic. The teeth are smooth, and compressed. The length of the metacarpal with the part of the shaft preserved is six and onehalf inches; the fore and aft extent of the condyles fourteen lines; the transverse extent about thirteen lines. This would indicate an expanse of wings of not less than twenty feet! The species, which is the first found in this country, may be named Pterodactylus Oweni, in honor of Professor Richard Owen, of London. The remains now representing it were discovered by the writer, in November last, in the upper Cretaceous formation of Western Kansas.

7. Earthquakes-Subterranean electrical disturbances.- A few minutes before and after the earthquakes of the 17th March last powerful positive electrical currents were rushing toward England through the two Anglo-American telegraph cables, which are broken near Trinity Bay, Newfoundland. Mr. C. F. Varley, C.E., who informed us of the fact, broaches the novel speculation that some earthquakes may be due to subterranean lightning.-Nature, Apr. 20.