Графични страници
PDF файл
ePub

FRESH-WATER GASTEROPODA.

MELANTHO DECISUS, Say.

(OPERCULATE)

Hamilton Bay. Some very fine specimens from Dundas Marsh

[blocks in formation]

I have at least three species of Amnicola from Hamilton Bay not yet named.

(NON-OPERCULATE.)

LIMNOEA PALUSTRIS, Mull.

A very variable shell, common in all streams and the inlets of
Hamilton Bay.

LIMNŒA CAPERATA, Say.

Taken in the same stream as Sphærium occidentale.

LIMNEA HUMILIS, Say.

From torrent in Chedoke Ravine, May 13th; Dundas Ravine,
May 24th.

LIMNOEA STAGNALIS, Linn.

Common in inlets of Hamilton Bay and in Dundas Marsh. This species appears to be found in many different parts of the world.

LIMNEA DESIDIOSA, Say.

Taken abundantly in September at Isle D'Orleans, near
Quebec.

LIMNŒEA CATASCOPIUM, Say.

A single specimen was found in the same locality as the last.
Some specimens of Limnoa taken in our district this season may

prove to be different to the above, while Limnoa catascopium will, I expect, be found in Lake Ontario.

PHYSA GYRINA, Say.

Scarce in different pieces of water in this neighborhood. PHYSA ANCILLARIA.

A few specimens were picked up on the shore at Port Dover, and it may be found here in the Lake.

The Rev. G. W. Taylor has retained nearly all my Physas for further examination. I expect to get at least two more species from among them.

BULINUS HYPNORUM, Linn.

Abundant in small streams running through open woods.
Some fine specimens have been secured this year.

PLANORBELLA CAMPANULATA, Say.
HELISOMA TRIVOLVIS, Say.

HELISOMA BICARINATUS, Say.

The last three species abound in stagnant pieces of water in our district.

SEGMENTINA ARMIGERA, Say.

A single specimen was taken in Dundas Marsh on May 6th. A peculiarity of this shell is that it has five small teeth at some distance from its mouth; in fact to see these teeth plainly it is necessary to break away a portion of the shell.

GYRAULUS

Several species from Hamilton Bay and Dundas Marsh have not yet been determined. G. deflectus and G. hirsutus should be among them.

ANCYLUS RIVULARIS, Say.

A few specimens were found attached to the valves of dead
Unios, cut out of the ice after the storm of Jan. 9th.

TERRESTRIAL GASTEROPODA.

(OPERCULATE.)

POMATIOPSIS LAPIDARIA, Say.

A terrestrial species of a fresh-water genus,

This shell is new

to the Canadian list, but is comman in some parts of the United States. It was first collected on Nov. 15th, last year, in a ravine running down to the Marsh, and has been found this year to be generally distributed around the Marsh, but has not been taken in abundance.

HYALINA NITIDA, Say.

(NON-OPERCULATE.)

Common everywhere in damp places, under logs, etc. HYALINA INDENTATUS, Say.

A few specimens only have been found under moss on decaying stumps and logs, along the side of the Mountain.

One or two species of Hyalina are still to be determined. PATULA ALTERNATA, Say.

PATULA STRIATELLA, Anthony.

These two species are common everywhere in woods and damp spots.

PATULA PERSPECTIVA, Say.

This shell appears to be rare here, a few only having been found along the side of the Mountain.

MESOMPHIA FULIGINOSUA.

Taken May 5th, on a mossy bank, at the mouth of a ravine running down to the Dundas Marsh. One specimen only was found last season.

TRIODOPSIS PALLIATA, Say.

Not common. Along the Mountain side.

TRIODOPSIS TRIDENTATA, Say.

In same locality as the last species, but more abundant. STENOTREMA MONODON, Rackett.

A variable shell. One or two specimens only have been taken. STENOTREMA MONODON, Rackett. var. FRATERNUM.

This is considerably larger than the type and has the umbilicus closed. It is common in woods.

MESODON ALBOLABRIS, Say.

MESODON THYROIDES, Say.

Both the above species are abundant throughout this district.

MESODON SAYI.

A rare shell, only one specimen having been taken here last season, the exact locality being unknown. This species, at first sight, somewhat resembles M. thyroides, but has a much larger umbilicus, also a small tooth on the lip which may be easily overlooked. On Good Friday, April 19th, a dead specimen was obtained in the ravine, under the Albion Mills, showing one locality, at any rate, where it may be found. FRUTICICOLA CANTIANA.

Observed in thousands along the heights overlooking the St. Lawrence River, near Quebec, last September. This Helix has been imported from England or Europe, and perhaps it is only a question of time before it has travelled this way.

FERRUSACIA SUBCYLINDRICA, Linn.

Common on banks and in open woods under logs.

STROBILA LABYRINTHICA, Say.

A few specimens were taken from a stream in woods, March 16th. PUPA CONTRACTA, Say.

Found in a stream in woods.

PUPA CORTICARIA, Say.

Found in a stream in woods and also under loose bark on logs. PUPA ARMIFERA, Say.

Very common on a dry, sunny bank overlooking Hamilton Bay, towards the Valley Inn, March 17th.

PUPA FALLAX, Say.

In same locality as last species, but much more rare. Only once previously reported from Canada.

CARYCHIUM MINIMUM.

Common everywhere in damp spots under logs. This is the smallest shell yet taken.

SUCCINEA OBLIQUA, Say.

SUCCINEA AVARA, Say.

These two Succineas are common in woods near streams.

SUCCINEA OVALIS.

Common along the shores of the Dundas Marsh and some

parts of Hamilton Bay.

Two species of Pupa and three other varieties of small land shells, taken this season, have not yet been determined.

GEOLOGICAL NOTES.

BY D. F. H. WILKINS, B. A., BAC. APP. SCI., PRINCIPAL, HIGH SCHOOL, BEAMSVILLE.

Read before the Hamilton Association.

Among the many interesting features of the rocks of Western Ontario are some to which, it is believed, attention has not as yet been directed One of these may be noted as occurring on and near the Credit River, Streetsville, Peel County, Ontario, and as presenting to us as nearly as possible the junction between the Hudson River or Cincinnati Group, the highest member of the Upper Cambrian or Lower Silurian of Murchison, and the Medina Group, the lowest but one member of the true Silurian or Upper Silurian of the famous geologist referred to. The flat, generally clay country of Peel county slopes gradually south-westward to the Credit River at Streetsville, and on the north-east bank of this stream may be seen, below some six to ten feet of clay, a series of greenish gray sandstones and argillo-arenaceous shales, some of the former being sufficiently thick-bedded to afford good flagstones. The series extends, as may indeed be clearly seen, under the river, and has a thickness exposed on the bank of from eighty to ninety feet. Moreover, from the more weathered shales and sandstones may be procured the following fossils typical of the Hudson River or Cincinnati Group;-Tetradium fibratum, Columnaria alveolata, Favistella stellata, Favosites hemispherica, Petraia Canadensis, Ambonychia radiata, Modiolopsis modiolaris, Avicula demissa, Strophomena alternata, Orthis testudinaria, and more rarely, Orthis occidentalis and fragments of an undetermined Orthceras. The river here has a well defined trend, south, twenty degrees east, or nearly so, and thus nearly conformable to the strike of the strata, this latter being more accurately south, twenty-five degrees east, the dip being, of course, south of west, at a very low angle. The floodplain of the river varies from a hundred feet to a hundred yards in

« ПредишнаНапред »