Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 23, 2025
I examined the deposits at Hoxne in 1860, when I had the advantage of being accompanied by the Reverend J. Gunn and the Reverend S.W. King. With it, but much more rare, were Limnaea palustris, Planorbis albus, P. Spirorbis, Succinea putris, Bithynia tentaculata, Cyclas cornea; and Mr. Prestwich mentions Cyclas amnica and fragments of a Unio, besides several land shells.
Physa columnaris, Desh. Melanopsis buccinoidea, Ferr.; recent. The univalve shells most characteristic of fresh-water deposits are, Planorbis, Limnaea, and Paludina. Neritina globulus, Def. Nerita granulosa, Desh.
Sometimes entire skeletons have been discovered within a few feet of the surface, in peaty earth at the bottom of small ponds, which the agriculturists had drained. The shells in these cases belong to freshwater genera, such as Limnaea, Physa, Planorbis, Cyclas, and others, differing from European species, but the same as those now proper to ponds and lakes in the same parts of America.
In this marly stratum many reptiles, several insects, and some fresh-water shells of the genera Paludina, Planorbis, and Cyclas, were found. Mr.
We found specimens of a Planorbis in the mud of the stream, and saw apparently a boring shell in the alluvium, but could not land to examine it. Chalky masses of alligators' droppings, like coprolites, are very common, buried in the banks, which become twenty feet high at the junction with the Ganges, where we arrived on the 14th.
The Planorbis is another well-known example. In this case we have a species evolving along several distinct lines into forms which differ remarkably from each other. The Tertiary mammals, living generally on the land and only coming by accident into deposits suitable for preservation, cannot be expected to reveal anything like this sensible advance from form to form.
There is no evidence to show whether the alleged progenitors of our British species were created in Siberia, Hungary, or Tibet. There is scarcely any variation either in the form or number of the species in those remote localities. Of Planorbis scarcely more than fifteen species inhabit the whole Caucasian province, and we have eleven of them in Britain."
Cyprides from the Upper Purbeck. a. Cypris gibbosa, E. Forbes. b. Cypris tuberculata, E. Forbes. c. The highest of the three divisions is purely fresh-water, the strata, about fifty feet in thickness, containing shells of the genera Paludina, Physa, Limnaea, Planorbis, Valvata, Cyclas, and Unio, with Cyprides and fish.
The pond, with its Planorbis eggs turning round and round, would have given us a few data for the first problem; the Mole, going bad under conditions not too repulsive, will tell us something about the second: he will show us the working of the crucible wherein all things are melted to begin anew. A truce to nice delicacy!
The fresh-water basins were filled with Helices, one of which is represented in the following wood-cut, with Planorbis, Limnæus and other Shells resembling those now so common in all our lakes and rivers, and differing from the living ones only by slight specific characters.
Word Of The Day
Others Looking