rocks, and in the upper part of the Hudson River group at the west. Dictyonema is a genus known from Lower Silurian to Devonian strata.

Graptolithus proper extends to the Clinton group of New York; and the same is true of Reteograptus. Tamnograptus occurs in the rocks of the Hudson River group near Albany, and in the Quebec rocks. Phyllograptus and Retiolites are known in the Quebec rocks only; while the typical form of Dendrograptus occurs in the Potsdam sandstone, and, likewise, in three other species, in the Quebec rocks.

We find, therefore, in the other genera, except trilobites, very little satisfactory evidence on which to rely in the present state of our knowledge, for determining the position of these strata.

In the present discussion, it appears to me necessary to go further, and to inquire in what manner we have obtained our present ideas of a primordial, or of any successive fauna. I hold that in the study of the fossils themselves there were no means of such determination prior to the knowledge of the stratigraphical relations of the rocks in which the remains are inclosed. There can be no scientific or systematic paleontology without a stratigraphical basis. Wisely then, and independently of theories, or of observations and conclusions elsewhere, geologists in this country had gone on with their investigations of structural geology. The grand system of the Professors W. B. and H. D. Rogers had been wrought out not only for Pennsylvania and Virginia but for the whole Appalachian chain; and the results were shown in numeous carefully worked sections. In 1843, '44 and '45 I had myself several times crossed from the Hudson River to the Green Mountains, and found little of importance to conflict with the views expressed by the Professors Rogers in regard to the chain farther south, except in reference to the sandstone of Burlington, and one or two other points, which I then regarded as of minor impor tance.

Sir William Logan had been working in the investigations of the geology of Canada; and better work in physical geology has never been done in any country.

This then was the condition of American geology, and investigators concurred, with little exception, in the sequence based on physical investigations. As I have before said, our earliest determinations of the successive faunæ depend upon the previous stratigraphical determinations. This I think is acknowledged

by Mr. Barrande himself, when he presents to us, as a preliminary work, a section across the centre of Bohemia. With all willingness to accept Mr. Barrande's determination, fortified and sustained as it is by the exhibition of his magnificent work upon the trilobites of these strata, we had not yet the means of parallelizing our own formations with those of Bohemia by the fauna there known. The nearest approach to the type of primordial trilobites was found in those of the Potsdam sandstone of the northwest, described by Dr. D. D. Owen; but none of these had been generically identified with Bohemian forms;* and the prevailing opinion, sanctioned as I have understood by Mr. Barrande, was that the primordial fauna had not been discovered in this country, until the re-discovery of the Paradoxides Harlani, at Braintree, Mass. The fragmentary fossils published in vol. 1, Palæontology of New York, and similar forms of the so-called Taconic system, were justly regarded as insufficient to warrant any conclusions. It then became a question for palæontologists to decide, whether determinations founded on a physical section in a disturbed and difficult region of comparatively small extent, were to be regarded as paramount to determinations founded on examinations, like those of the Professors Rogers, extending over a distance in the line of strike of five or six hundred miles; and those of Sir William Logan over nearly as great an extent from Vermont to Gaspé.

It is not possible for me, at this moment, to give the time necessary for a full discussion of this important subject. In presenting these few facts in this form, I am far from doing it in the spirit of cavilling, or as an expression of distrust in any direction. It is plain that the case is not met in Mr. Barrande's plan of successive trilobitic fauna; and the facts yet brought out do not serve to clear up the difficulty. It is evident that there is an important and perplexing question to be determined,—one that demands all the wisdom and sagacity of the most earnest inquirers, and one which calls for the application of all our knowledge in stratigraphical geology and in paleontology;-one in which coöperation, good will and forbearance are required from every one, to harmonize the conflicting facts as they are now presented. The occurrence of so many types of the second fauna in the rocks at Point Levi, associated with a smaller number of estab

The glabella of small trilobites undistinguishable from Conocephalus occur in the Potsdam sandstone near Trempaleau, Wisconsin, on the Mississippi river.

lished primordial types, offers us the alternative of regarding these strata as of the second stage, with the reappearance of primordial types in that era, or of bringing into the primordial zone several genera heretofore regarded as beginning their existence in the second stage: in either case, so far as now appears, conflcting with the scheme of Mr. Barrande in reference to the successive fauna of trilobites as established in Bohemia and the rest of Europe.

For myself I can say, that no previously expressed opinion, nor any "artificial combinations of stratigraphy previously adopted" by me, shall prevent me from meeting the question fairly and frankly. I have not sought a controversy on this point, but it is quite time that we should all agree that there is something of high interest and importance to be determined in regard to the limitation of the successive fauna of our older palæozoic rocks.

I am, yours, &c.,

JAMES HALL.

Albany, N.Y., Jan. 23, 1861.

ARTICLE VIII.-Catalogue of Plants collected in the Counties of Argenteuil and Ottawa, in 1858. By W.S. M. D'URBAN. The following list of Plants contains 362 species, all of which were collected strictly within the Laurentian district, many introduced species growing on the fossiliferous rocks in the immediate neighbourhood of the town of Grenville, being omitted. A large portion were determined by myself on the spot with the aid of Dr. Asa Gray's admirable "Manual of the Botany of the Northern United States," which was my almost constant companion during the five months I spent in the district, but I have to acknowledge my obligations to Mr. G. Barnston, who kindly assisted me in naming some phenogamous species; to Col. Munro, C. B., 39th Regt., who most obligingly determined the whole of the sedges and grasses; to Mr. D. Allan Poe, who examined the cryptogams, and named all the mosses, some of which he submitted to the eminent bryologist, Mr. James of Philadelphia; and lastly to Dr. Dawson for allowing me unlimited access for purposes of reference to the Holmes herbarium deposited in McGill College.

Many of the specimens collected were so small and depauperated in form, from the poverty and scantiness of the soil that I found it

very difficult to recognise them at the first glance, and even when compared with specimens gathered in the rich limestone districts, it was with difficulty I could believe them to be the same species, until I had made a very close examination.

A considerable number of European plants were found round clearings, lumber roads, and along the banks of the Rouge, and I have indicated such as were obviously introduced, by an asterisk. (*)

For the sake of brevity I have given the English names of some of the commoner species only, and in general those under which they are known to the settlers and lumbermen. With the assistance of the other members of our party, I was enabled to obtain the Indian names of a few species, and they will be found below, spelled, I believe correctly, in accordance with their pronunciation. They were furnished by the son of the Algonquin chief of the Indian settlement on the Rouge, in the township of Arundel, called "Chi-chick" (pronounced Shes-sheep), who could read and write his own language, and understood both English and French.

I have given the dates at which I found most of the flowering species in full flower, (F.) and their fruit ripe, (F. R.) believing they may be useful in indicating the climate of the district.

When no locality in particular is mentioned the plant was distributed over the whole district.

LONDON, ENGLAND, May 16th, 1860.

Ranunculacea (Crowfoot Family).

Clematis Virginiana, Linn. Abundant in swamps; F. 12th August. Anemone Pennsylvanica, Linn. In great abundance and luxuriance on a clearing near the Devil's rapids on the Rouge; F. 30th June to 18th July.

Thalictrum cornuti, Linn. Abundant in moist places; F. 16th July. Ranunculus Flammula, Linn., var. reptans. Amongst stones by the water-side, River Rouge, near Silver Mountain; F. 5th August.

Pennsylvanicus, Linn. Abundant in wet places, Hamilton's Farm; F. 30th June.

25 acris, Linn. Clayey banks of the Rouge and round clearings; F. 13th June.

Caltha palustris, Linn. Marshy ground, clearings along Chatham, North Town.

Coptis trifolia, Salisb. Very abundant in rocky woods and swamps;

F. 31st May.

Aquilegia Canadensis, Linn. A few stunted plants on gneiss rocks, Sixteen Island Lake; F. 3rd June.

Actæa spicata, Linn., var. rubra, Michx. Abundant in rocky woods; F. R., end of July.

var. alba, Michx. Woods near Hamilton's Farm.

Cabombacea (Water-shield Family).

Brasenia peltata, Pursh. Abundant in lakes and ponds. Nymphæacea (Water-lily Family).

Nymphæa odorata Ait. Bark Lake, Arundel; F. 17th July. Nuphar advena, Ait. Abundant in most lakes; F. 28th June. Sarraceniacea (Pitcher-plant Family).

Sarracenia purpurea, Linn. (Ta-na-da-tas, Algonquin). Common in bogs or Beaver-meadows; F. July.

Papaveracea (Poppy Family).

Sanguinaria Canadensis, Linn. (Blood root). Clearings on crystalline limestone, Wentworth.

Fumariacea (Fumitory Family).

Dicentra Cucullaria, DC. Abundant in woods on crystalline limestone; F. 15th May.

Corydalis glauca, Pursh. Sparingly on gneiss rocks, Sixteen Island Lake and Huckleberry rapids on the Rouge; F. 15th June to 17th July.

Crucifera (Mustard Family).

Dentaria diphylla, Linn. (Indian Pepper). Rocky woods; F. 30th

May.

Cardamine hirsuta, Linn. A very small form; growing submerged by the sides of the Rouge near Silver Mountain, and

in wet places on Hamilton's Farm.

Capsella bursa-pastoris, Moench. Abundant about clearings. Violacea (Violet Family).

Viola rotundifolia, Michx. Locality not noted.

" blanda, Willd. Rich woods, generally on limestone; F. 17th

May.

"L Selkirkii, Goldie. Gate Lake, Wentworth; F. 17th May.

"L cucullata, Ait. Very abundant and luxuriant about the French settlement in Wentworth, also moist places about clearings on Bevin's Lake, Montcalm; F. 4th June. Canadensis, Linn. Very abundant and luxuriant, French settlement, Wentworth; F. 4th June.

"6 pubescens, Ait. Rich low woods on crystalline limestone; F. beginning of June.

Droseracea (Sun-dew Family).

Drosera longifolia, Linn. Sphagnum and swamp round a small pond near the Indian Village on the Rouge, and on pine logs in a small lake near Lake of Three Mountains.

Hypericaceae (St. John's-wort Family).

Hypericum ellipticum, Hook. Sandy banks of the Rouge; F. 14th July to 21st August.