southeast of Georgian bay by way of the Trent valley into Lake Ontario, at about sixty miles west of the present outlet of this lake. The outlet of this upper lake was 26 feet deep where it connected with the Trent valley, and the channel was from one to two miles wide. This, for a few miles, is cut across a drift ridge to a depth of 500 feet. With the continued continental uplift to the northeast (which has raised the old beach at the outlet, into the Trent valley, about 300 feet above the present surface of Lake Huron), the waters were backed southward and overflowed into the Erie basin, thus making the Erie outlet of the upper lakes to be of recent date. This is proven by the fact that the beach, which marked the old surface plain of the upper great lake, descends to the present water level at the southern end of Lake Huron. Erie the youngest of all The Great Lakes. The Erie basin is very shallow, and upon the dismemberment of Lake Warren was drained by the newly constructed Niagara river (except perhaps a small lakelet southeast of Long point). Subsequently the northeastward warping (very much less in amount than farther northward at the Trent outlet) eventually lifted up a rocky barrier and formed Erie into a lake in recent times, thus making Erie the youngest of all the lakes. The beaches about Cleveland are not those of separated Lake Erie, but belong to the older and original Lake Warren. NOTE. To distinguish from the modern, the ancient valley of the St. Lawrence, above described, is named the "Laurentian;" the ancient river from the Erie basin, the Erigan; the Huron-Michigan-Superior lake, the Algonquin, as also the beach which marked its shores, and the river which discharged its waters by the Trent valley. The expanded, but separate, Lake Ontario is named the Iroquois, as also its principal beach, now at 116 feet above its modern surface, at the extreme western end of the lake, while at about 135 miles northeastward (near Trenton) its elevation is 435 feet. REMARKS ON AN UNDESCRIBED VEGETABLE ORGANISM FROM THE FORT UNION GROUP OF MONTANA. By Prof. LESTER F. WARD, U. S. Geological Survey, Washington, D. C. [ABSTRACT] THE specimens were collected in 1883 at two points forty miles apart and on opposite sides of the Yellowstone in the vicinity of Glendive, Montana. At one of the localities, viz., Iron Bluff, twelve miles above that town and on the right bank of the river some fifteen meters above low water mark, it occurs in a red burned cliff in light arenaceous clay, the specimens being very large, sometimes measuring thirty centimeters across. At the other locality, namely Burns' Ranch, twenty-eight miles below Glen dive on the left bank of the river and close to the water's edge, the specimens are smaller and more perfect, being embedded in a fine grained bluish clay shale. The fossil shows a large circular center 2-7cm. in diameter from which there proceed in radial arrangement in all directions a large number of single flexible stems varying in length and having a width of 2-3 mm. These horizontal, radiating stems are sometimes slightly sinuous, lying upon and often crossing one another. They exhibit for most of their length, beginning near their attachment to the center, a row of toothlike appendages on each side, which are about mm. in width at the base and about 1mm. apart, obliquely ovate in shape with obtuse tips and always projecting forward toward the distal end of the stem at an angle of 50°. Close examination with a high power reveals the presence of a continuous epidermal membrane composed of hexagonal cells connecting these projections. The stems are uniform in width and not marked by any longitudinal costa until within some 3cm. of the apex when they expand into an elongated elliptic blade, or head, terminating the stem. Through the center of each of these heads run two rows of what appear to be sporecases, one on each side of the median line and separated from each other by a very narrow interval forming a continuous groove running longitudinally through the head. The supposed spore-cases are somewhat elongated transversely, and arranged in pairs, filling most of the surface of the head, but leaving a winged expansion at the central or widest portion. They average 14mm. in length and mm. in thickness. Below the base of the head, where the teeth begin, they appear to cease, but in most cases a careful inspection reveals their presence in an obsolete and probably functionless form, and this is sometimes distinguishable for considerable distance down the stem where it assumes more the aspect of a series of articulations widening as the center is approached. The lateral teeth of the stems usually cease below the head, but cases occur in which they continue for some distance along the margins of the expanded lamina. Considerable, but not as yet exhaustive, search has been made through the literature of paleontology to find the analogues and determine the affinities of this singular organism, as yet almost entirely without success, the forms figured under the names Discophorites, Gyrophyllites and Tænidium, perhaps having the greatest resemblance, but not close enough to indicate any relationship. Specimens have been shown and sent to a number of eminent paleobotanists and paleontologists, but none, so far as heard from, can give any idea of its nature. Its vegetable character having been questioned it has also been shown or sent to the best authorities on invertebrate zoology in this country and in Europe. Those who have thus far expressed an opinion have uniformly denied its relation to any known animal. It is remarkable that it is the botanists who have suggested its possible animal nature, the zoologists inclining to regard it as a plant. Having collected and long studied the specimens, superintended their delineation, and compared them with a great number of forms both fossil and living, I may be permitted to advance in as few words as possible, the theory which I provisionally hold as to the nature of this organism, as follows: I am disposed to regard it as a "comprehensive type" of vascular cryptogamic life, embodying some of the characters of several well known living types, viz., 1. The large tufted central base is suggestive of that of most species of Isoetes, and the long weak stems of certain of these species are observed to recline and lie prostrate in all directions around this center. 2. The double row of spore-cases at the apex of the stem agrees in all essential respects with that of Ophioglossum, and the elliptic expansion may be regarded as homologues of the larger blade-like fronds of that genus, which may easily be imagined to have the spores borne along its median line instead of on a special fruiting frond. 3. The prostrate sinuous habit is not widely unlike that of certain creeping species of Lycopodium, as, e. g., L. annotinum, and the toothlike appendages may be the reduced homologues of the scale-like leaves of that genus. 4. A still further approach is seen in Selaginella where the scales have become distichous and the stems flat and closely creeping. This parallel is well-nigh complete in those species, such as S. Douglasii, in which the spores are borne in terminal spikes, like those of most Lycopodiums, except that these are more or less flattened and two-ranked. 5. Finally, ignoring the appendicular organs of Marsilia we see in the fruit-bearing portion a further analogy to our fossil, the fruiting stems radiating from the thickened base and bearing the spores at their apex.1 The fossil would thus represent a highly generalized type and may be phylogenetically related to all these more specialized modern forms with each of which it seems to possess some characters in common. The paper was illustrated by lantern views of the original fossils and of carefully prepared drawings. By Prof. LESTER THE PALEONTOLOGIC HISTORY of the genus PLATANUS. [ABSTRACT] THE genus Platanus is one of those waning types, like Ginkgo, Sequoia, Liriodendron, etc., of which so much has been said of late, and though now constituting an entire order and containing only seven species, it is evidently the descendant of a large family embracing a number of genera, each with a fair representation of specific forms. Twenty extinct species of Platanus are now recorded from Tertiary and Cretaceous strata, which are, however, in most cases founded on the impressions of leaves. But in 1 Since the date at which this paper was read communications have been received from the Marquis Saporta and from Dr. A. G. Nathorst, both of whom agree that the organism is probably a cryptogamic plant related to Ophioglossum. 2 Published in full in the Proceedings of the United States National Museum, Washington, 1888, Vol. XI, pp. 39-42, pls. xvii-xxii. addition to these there is a large number of aberrant types resembling Platanus in many respects, though also resembling some other living genera, which have been variously referred to Sassafras, Aralia, Liquidambar, Liriodendron and to the supposed extinct genera Araliopsis, Aspidiophyllum, Protophyllum and Credneria. The object of this paper was to point out the probable genetic relationship among all these extinct types and to show that they are the probable ancestors of the modern genus Platanus. Special emphasis was laid upon the significance of the basilar lobes of the form described by the author as Platanus basilobata from the Fort Union group, and upon the connection between this and similar appendages sometimes found on leaves of P. occidentalis, and of certain fossil species of Platanus, Aralia, and Aspidiophyllum. The supposed Sassafras leaves of the Dakota group were also discussed with a view to showing that they are also archaic platanoid types, and it was argued that the nervation of these leaves differs in some fundamental respects from that of the leaves of the only living species of that genus, the normal form of which was shown to be entire and not trilobate, as is commonly supposed. Finally, it was contended that, inasmuch as five of the seven living and a large preponderance of the fossil species of Platanus, as well as most of the ancestral forms referred to, are American, and as the type is found in this country in very much older strata than in the Old World, it must be conceded that, notwithstanding the historic antiquity of the oriental plane tree in connection with the early development of the human race in Asia and Europe, nevertheles it is, paleontologically, an American tree, and had its origin in this country. This paper was illustrated by lantern views of fifteen of the forms selected to exhibit the phylogenetic development of the genus. EVIDENCE THAT LAKE CHEYENNE CONTINUED TILL THE ICE AGE. [ABSTRACT.] By THIS paper called attention to several facts hitherto unpublished which indicate that eastern Nebraska, western Iowa and southeast Dakota were occupied by a fresh water lake when the drift first began to be deposited in that region. The facts and considerations are as follows: 1. An extensive deposit of fine sand containing a few fossil bones, overlain in some places by a lead-colored clay without pebbles, and some fossiliferous silt resembling loess, is found occupying much of the region, especially at lower levels. Ten localities were mentioned where these formations have been observed, the more notable being Fairview, Dak., Mills Co., Iowa, and Lancaster Co., Neb. A large fossil claw of some gigantic mammal' was shown which was obtained from Mills Co., Iowa, in the sand below the drift. 2. The occurrence of a stratum of volcanic ashes in such position as to show that wide areas were occupied by still water, just preceding the deposition of the drifts in some parts and during it in others. The localities described and pictured were in Knox Co., Neb., and near West Point, Neb. 3. An objection which may be urged, from the depth of the channel of the Missouri in this region, is removed by several facts which go to show that said channel has been wholly excavated since the glacial epoch. (a) The rock under the present bed is unglaciated and unoccupied by drift deposits, as has been recently demonstrated by observations made in sinking the piers of bridges at Blair and Omaha. (b) The Missouri is still deepening its trough with every great flood. This has been determined by soundings at such times. This fresh water lake, from its time and location, may be quite confidently considered a portion of the great body of water which occupied the western plains during late Tertiary times, and which was named by King, Lake Cheyenne. THE TERRACES OF THE MISSOURI. By Prof. J. E. TODD, Tabor, Iowa. LABSTRACT.] THIS paper embodies the observations of the writer while connected with the U. S. Geol. Survey, during the last six years. They extend from the 41° to the 46° of latitude. The terraces are found to be readily arranged in three groups, viz. : The Silt Terraces, which rise from 5 to 175 feet above the present stream, the Lower Bouldery terraces, from 70 to 350 feet, both these being much higher toward the north, and the Higher Bouldery Terrace, which has been less definitely and extensively traced, rising from 350 to 475 feet. The development, location and structure of the different terraces were discussed in detail. All decline in height down stream. All contain coarse material, boulders and gravel, but this is especially prominent in the bouldery terraces, and in all this diminishes in amount down stream. Even the bouldery terraces are commonly capped with silt several feet in depth. The lower silt terraces were not considered; the highest one of this class was observed at Pierre to be 160-125 feet above the river; near Crow Creek Agency, 150-110; at Chamberlain, 125; ten miles above Wheeler, 85; Wheeler, 105-85; Fort Randall, 30-45; and at Niabrara, about 25 feet above the river. 1 Since the above was written this has been determined by Professor Leidy to be a claw of Megalonyx. |