Truncatulina lobulata.

Fossil-Leda clay, Labrador; Rivière-du-Loup.

Recent Gulf St. Lawrence, very common 30 to 50 fathoms. This species is much less common in the Post-pliocene than in the recent.

Orbulina universa..

Fossil-Leda clay, Montreal; Rivière-du-Loup; Labrador. This may be regarded as a rare and somewhat doubtful Postpliocene fossil. It has not yet been recognized in the Gulf of St. Lawrence.

Globigerina bulloides.

Fossil-Rivière-du-Loup.

Recent Gulf St. Lawrence, more especially in the deeper water, where it is common.

Pulvinulina repanda.

It is very rare in the Post-pliocene.

Fossil-Montreal, Leda clay; Rivière-du-Loup; Murray Bay; Labrador; Quebec; Portland (Maine).

Recent Gulf St. Lawrence, 30 to 313 fathoms, G. M. D. Somewhat rare both in the Post-pliocene and recent, and of the small size usual in the arctic seas.

Polystomella crispa.—(Var. Striatopunctata). (Var. Arctica.)

Fossil-Montreal, Leda clay; Labrador; Rivière-du-Loup; Murray Bay; Quebec; Portland (Maine); St. John, N. B. Recent-Gulf and River St. Lawrence, 30 to 40 fathoms. G. M. D.

Very common, especially in depths of 10 to 40 fathoms. This is by far the most abundant species in the Post-pliocene deposits, as it is also in all the shallow parts of the Gulf of St. Lawrence at present, and also in the Arctic Seas, according to Parker and Jones. It is the only species yet found in the Boulder-clay of Montreal, and this very rarely.

Nonionina scapha.

(Var. Labradorica.)

Fossil-Leda clay, Montreal; Rivière-du-Loup; Labrador; Murray Bay; Quebec; St. John, N. B.

Recent-Gulf and River St. Lawrence, 10 to 313 fathoms. Var. Labradorica is the deeper water form and is rare in the Leda clay.

Textularia pygmæa.

Fossil-Leda clay, Labrador; Rivière-du-Loup; Quebec; also at Portland (Maine).

Recent Gulf St. Lawrence, 10 to 30 fathoms.

The Textulariæ are rare and of small size, both in the Postpliocene and recent.

Cornuspira foliacea.

Fossil-Leda clay, Montreal.

Recent Gulf St. Lawrence, 16 to 250 fathoms, G. M. D. This species is rare both fossil and recent.

Quinqueloculina seminulum.

Fossil-Leda clay, Montreal; Labrador; Quebec; Portland (Maine).

Recent Gulf St. Lawrence, 10 to 313 fathoms, most abundant in shallow water. G. M. D.

This species is by no means common and not usually large in the Post-pliocene. It is more abundant in the clays of Maine than in those of Canada.

Biloculina ringens.

Fossil-Leda clay, Montreal; Labrador; Rivière-du-Loup; Murray Bay; Quebec.

Recent Gulf St. Lawrence, 30 to 313 fathoms. G. M. D. Rather rare in the Post-pliocene as well as in the recent.

Triloculina tricarinata.

Fossil-Leda clay, Rivière-du-Loup; Murray Bay; Quebec. Recent Gaspé, 30 to 50 fathoms. G. M. D.

Rare both in Post-pliocene and recent, but perhaps more generally diffused in the former.

Lituola and Saccammina.

A very few minute sandy forms referable to these genera are found among the finer part of the washings from Riviére-du-Loup. Euglypha?

A single minute test, apparently identical in form with that of Euglypha alveolata, was found in washing the Rivière-du-Loup clays.

In general terms it may be stated that all the species of Foraminifera found in the Post-pliocene stiil inhabit the Gulf and River St. Lawrence. Several species found in the Gulf of St. Lawrence have not yet been recognized in the Post-pliocene, and these are mostly inhabitants of depths exceeding 90 fathoms, or among the more southern forms found in the Gulf.

On the whole, the assemblage, as in the northern part of the Gulf of St. Lawrence at present, is essentially arctic, and not indicative of very great depths.

The sandy forms which are not uncommon in the Gulf are very rare in the Post-pliocene; but this may be accounted for by the greater difficulty of washing them out of the clay, or possibly their cementing material may have decomposed, allowing them to fall to pieces. As the epidermal matter of shells is often preserved, the last supposition seems less likely. The Leda clays are, however usually very fine and calcareous, so that there was probably more material for calcareous than for arenaceous forms.

The Foraminifera are very generally diffused in the Post-pliocene clays, though much more abundant in some layers than in others. They may easily be detected by a pocket lens, and are usually in as fine preservation as recent specimens, especially in the deeper and more tenacious layers of the Leda clay. They are however, usually most abundant in the somewhat arenaceous layers near the top of the Leda clay, and immediately below the Saxicava sand, and especially where this layer contains abundance of shells of Mollusca. I have nowhere found them more abundant or in greater variety than at the Glen Brick-work, Montreal, on the McGill College Grounds, and at Logan's Farm. At the Glen Brick-work a few worn specimens of Polystomella are contained in the beds underlying the Leda clay and equivalent to the Boulder-clay, which, however, has in general, in the vicinity of Montreal as yet afforded no marine fossils.

In searching for Foraminifera in the clays of Rivière-du-Loup, I have observed in the finer washings several species of Diatomacea; among these a species of Coscinodiscus very frequent in the deeper parts of the Gulf of St. Lawrence. But on the whole Diatoms appear to be rare in these deposits. In the Rivière-duLoup clays I have also observed the pollen grains of firs and

spruces.

The nomenclature used above is that of Parker and Jones, in their paper on the North Atlantic Soundings, in the Transactions VOL VI.

I

No. 3.

of the Royal Society. For figures of the spccics, I may refer to that memoir, and to my previous papers published in the Natur alist.

Tethea Logani, Dawson.

(2) Porifera.

Leda clay, Montreal. This species has not yet been recognised in a living state, though allied to Tethea hispida, Bowerbank, of the coast of Maine. Its spicules in considerable masses, looking like white fibres, are not uncommon in the Post-pliocene at Montreal.

Tethea?

Another silicious sponge is indicated by little groups of small spicules found at the Tanneries, near Montreal, by Mr. G. T. Kennedy, and at Riviere-du-Loup by the author. Its spicules are long and accrate, and much more slender than those of Tethea Logani. They resemble those of T. hispida, recent on the coast of Maine, and also those of a species of Polymastia, dredged by Mr. Whitcaves in the Gulf of St. Lawrence.

CLASS II-ANTHOZOA.

CLASS III.-HYDROZOA.

No distinct organisms referable to the above groups have yet been found in the Post-pliocene deposits of Canada. As our recent fauna includes no stony coral, and the recent species of the Gulf of St. Lawrence have no parts likely to be preserved other than minute spicules, this is not to be wondered at. In washing the clays for Foraminifera, however, numerous fragments are obtained, which resemble portions of the horny skeletons of hydroids, though not in a state admitting of determination.

CLASS IV.-ECHINODERMATA.

(1) Ophiuridea.

Ophioglypha Sarsii, Lutken.

Fossil-Leda clay, near St. John, N. Brunswick; Mr. Matthew. Recent River St. Lawrence, at Murray Bay; also found of large size in deep water in the Gulf of St. Lawrence, by Mr. Whiteaves.

Ophiocoma.

Fragments of a small species of ophiuroid starfish not determinable, have been found in the Leda clay at Montreal, and in nodules at Green's creek.

(2) Echinoidea:

Euryechinus drobachiensis, Müller.

Fossil-Leda clay, Beauport; Rivière-du-Loup; Montreal. This species is rare in the Post-pliocene, but very common in all parts of the Gulf of St. Lawrence at present.

(3) Holothuridea.

Psolus phantopus? Oken.

Scales of an animal of this kind have been found in the Leda clay at Montreal. They may belong to P. phantopus, or to the species P. (Lophothuria) Fabricii, also found on our coasts.

ON THE ORIGIN AND CLASSIFICATION OF
ORIGINAL OR CRYSTALLINE ROCKS.
By THOMAS MACFARLANE.

(Continued from page 312-Vol. V.)

V. MINERALOGICAL CONSTITUTION.

Having, in the foregoing, adverted to the texture and chemical composition of original rocks, it now becomes necessary to refer more particularly to their mineralogical constitution. In order to continue the analogy which has been shewn to exist between furnace slags and original rocks, it will be well here to refer to those instances which have been observed of the formation of well developed crystals in the cooling of artificial silicates. The rapid manner in which furnace slags are commonly allowed to cool is of course detrimental to the formation of any mineral-like aggregations, but it is sometimes possible to observe in copper furnace slags that, when they have been allowed to solidify in large blocks or cakes, they shew an actynolitic structure in their mass, often closely resemble hornblende rock, and very commonly contain cavities lined with the most beautiful crystals. The formation of pyroxene in slags from iron furnaces has been frequently observed