This land at length sank down and was submerged with its forests beneath a body of fresh water, from which sediment was thrown down enveloping fluviatile shells.
The prevalence of a downward movement is, no doubt, the principal cause which has saved so many extensive seams of coal from destruction by fluviatile action.
Alternations are there seen of beds containing fluviatile shells, with others filled exclusively with marine species; and I observed oysters attached to many limestone pebbles.
Had we discovered the ancient delta of some large Silurian river, we should doubtless have known more of the shallow, and brackish water, and fluviatile animals, and of the terrestrial flora of the period under consideration.
Fossil oysters (Ostrea bellovacina) abound in some places, and in others there is a mixture of fluviatile shells, such as Cyrena cuneiformis (fig.
Shells of the genus Cypris and Unio, collected by Mr. Bean from these Yorkshire coal-bearing beds, point to the estuary or fluviatile origin of the deposit.
The species are, for the most part, marine, but a few of them belong to land and fluviatile genera.
Rivers scarcely ever fail to carry down into their deltas some land shells, together with species which are at once fluviatile and lacustrine.
They have been carried away grain by grain by the denuding forces--by weathering, rain, frost, and fluviatile and marine action.
The fact being established that some of these lakes have no obvious connection with the river, it becomes probable that they are the remains of what the surface was before the fluviatile process began to carry off its waters.
Thus the fluviatile process seemed to be reversed here, the tendency of this river being not to carry surface waters off, but rather to spread over land where none could otherwise be found, those brought from a great distance.
These are in part of glacial origin, and contain Scandinavian boulders; but fluviatile and aeolian deposits also occur.
Germany and the Miocene of the Danube valley is also in part marine, but in central Germany it is of fluviatile or lacustrine origin.
The lowest or recent fluviatile deposits which occur beside the bed of the present river, are referable to the Recent period, as they contain the remains of none but living Mammals.
Sometimes the cave has been the bed of an ancient stream, and the deposits have been formed as are fluviatile deposits at the surface.
The important fact to remember about these fluviatile deposits is this--that here the ordinary geological rule is reversed.
When a river begins to occupy a particular line of drainage, and to form its own channel, it will deposit fluviatile sands and gravels along its sides.
As it goes on deepening the bed or valley through which it flows, it will deposit otherfluviatile strata at a lower level beside its new bed.
Or, again, the river has formerly flowed at a greater elevation than it does at present, and the cave has been filled with fluviatile deposits by the river at a time prior to the excavation of its bed to the present depth (fig.
The actual extent of the marine deposit inland cannot be defined, as it is covered by later fluviatile deposits.
The old alluvia (3) are obviously of fluviatile origin, and show us that after the deposition of the clays, etc.
The fauna in question is characteristically Pleistocene, nor can it be doubted that the Mosbach Sands belong to the same geological horizon as the similar fluviatile deposits of the Seine, the Thames, and other river-valleys in western Europe.
Such action being repeated year after year, it might well happen that many river-valleys might become largely filled with rudely alternating layers of frozen snow and fluviatile detritus.
Their excavation by fluviatile action certainly dates back to a period long anterior to the advent of the Ice Age.
In some cases they are at a considerable distance from the beach, and in these instances, so far as yet examined, there are proofs that the coast has advanced in consequence of upheaval or of fluviatile or marine deposit.
After the upheaval, or during it, the Mississippi cut through the whole fluviatile formation, of which its bluffs are now formed, just as the Rhine has in many parts of its valley excavated a passage through its ancient loess.
They are not marine, they are interstratified with beds of sand and silt, containing often delicate fluviatile shells, which were deposited when the stream ran tranquilly, as the coarser gravels were when it ran with a stronger torrent.
South and east of the country of the Koldagi we come to the Negroes of the White Nile (Bahr el Abiad); where the fluviatile character of the soil and the physical appearance of the occupants coincide.
Fluviatile alluvia (deltas of the Indus and Ganges).
It may be remarked in this place that the only other fluviatile invertebrate which I found in these waters was a white siliceous coating sponge, whose statoblasts were well visible to the naked eye.
Indeed, the latter event is incomplete in our times; for, though the marine Saurians have been almost entirely removed, the fluviatile and terrestrial ones maintain themselves, though diminished both in species and individuals.
The seven hills of Rome are of the Pliocene, with fluviatile deposits and recent terrestrial shells two hundred feet above the Tiber.
Of this genus there are some six species (the exact number, as in so many other genera, cannot be positively asserted), most of which are fluviatile or estuarine in habit.
It is also thought to be purely fluviatile and never to desert the rivers for the sea.
This does not signify much if the loess was formed in a lake subject to orographic oscillations, or if, as I am coming to believe, it is a fluviatile deposit of an oscillating river like the Hoang-Ho on the great Chinese plain.
The fossils contained in diluvial deposits consist, generally, of terrestrial, lacustrine, or fluviatile shells, for the most part belonging to species still living.
This land at length sank down and was submerged with its forest beneath a body of fresh water from which sediment was thrown down enveloping fluviatile shells.
The manuscript species of Mr. Dohrn will shortly appear in his intended work upon the land and fluviatile shells of Ceylon.
This need not necessarily exclude a fluviatile origin, but speaking generally that term now suggests an aerial rather than a subaqueous deposit.
It lay some five feet beneath the surface in a deposit which seems to be an ancient one of fluviatile origin.
In all cases, the cave-finds are assignable to a period later in time than that in which the fluviatile deposits (previously discussed) were formed.
In none of these cases can any hard and fast line be drawn, and some groups which are shore fishes in one region will be represented by semi-bathybial orfluviatile forms in another.
Are fluviatile and terrestrial animals, as a rule, better off than marine animals?
There are no fluviatile or terrestrial Echinoderms.
Frogs and Toads, unlike other fluviatile animals, develop with metamorphosis.
Crustacea, but, as in other animals, the terrestrial and fluviatile forms usually develop directly.
Among the few Cœlenterates which have no free planula stage is the one truly fluviatile genus--Hydra.
Larval stages are apt to be suppressed in fluviatile and terrestrial forms.
Drift timber and other fluviatilerelics lay high on the banks, and several weirs for catching fish, worked very neatly, stood on ground quite dry and hard.
A succession of low ridges seemed there to mark the extent of its basin, nor did I perceive in the country beyond any ranges of a more decidedly fluviatile character.
Occasionally lacustrine and fluviatile shells, or the bones of amphibious or land reptiles, point to the same conclusion.
Instead of the growth of coralline limestone, let us suppose, in some other place, the continuous deposition of fluviatile mud and sand, such as the Ganges and Brahmapootra have poured for thousands of years into the Bay of Bengal.
But if the bottom be lowered by sinking at the same rate that it is raised by fluviatile mud, the bay can never be turned into dry land.
Anderson is a purely fluviatile animal, which apparently never goes out to sea.
Anderson, who has fully described this species, says that he has "never observed it in tidal waters, so that it is even more strictly fluviatile than the Gangetic dolphin.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "fluviatile" in a variety of sentences. We hope that you will now be able to make sentences using this word.
