stood by the makers of genealogical trees. On the other hand, in spite of the millions of possible combinations which these ten characters may assume when affecting not simply a single combination, but all the combinations which might arise from their extending over several hundred species, we yet find that the combinations which actually exist - those which leave their traces as fossils fall immensely short of the possible number. We have, as I have stated, not more than twenty-three hundred species actually representing for the Echini the results of these endless combinations. Is it astonishing, therefore, that we should fail to discover the sequence of the genera, even if the genera, as is so often the case, represent, as it were, fixed embryonic stages of some Sea-urchin of the present day? In fact, does not the very history of the fossils themselves show that we cannot expect this? Each fossil species, during its development, must have passed through stages analogous to those gone through by the Echini of the present day. Each one of these stages at every moment represents one of the possible combinations, and those which are actually preserved correspond only to the particular period and the special combination which any Sea-urchin has reached. These stages are the true missing links, which we can no more expect to find preserved than we can expect to find a record of the actual embryonic development of the species of the present day without direct observation at the time. The actual number of species in any one group must always fall far short of the possible number, and for this reason it is out of the question for us to attempt the solution of the problem of derivation, or to hope for any solution beyond one within the most indefinite limits of correctness. If, when we take one of the most limited of the groups of the animal kingdom, we find ourselves engaged in a hopeless task, what must be the prospect should we attack the problem of other classes or groups of the animal kingdom, where the species run into the thousands, while they number only tens in the case we have attempted to follow out? Shall we say "ignorabimus," or "impavidi progrediamus" and valiantly chase a phantom we can never hope to seize?

PAPERS READ.

ON THE PROGRESS OF GEOLOGICAL INVESTIGATION IN NEW BrunsWICK, 1870-1880. By L. W. BAILEY, of Fredericton, N. B. To the student of the physical geography and geology of eastern America, I need scarcely say that the Province of New Brunswick possesses features of peculiar interest. Lying along the western border of the great St. Lawrence Gulf, and including the larger part of the great Acadian basin now above the sea level, it well exhibits in its different portions the peculiarities of that basin, and in the features of its rock-formations, the more prominent phases of its history. Adjoining also the extensive metamorphic tract of New England, from which spurs of highly crystalline rocks traverse portions of its area, it at the same time differs from the latter in being in general less profoundly altered, and in containing a much larger number of fossiliferous formations as horizons for its study. In this way it becomes, to a certain extent, a key to the geology of northeastern America, and as such, acquires a general as well as a local interest.

At the meeting of the Association in Salem, a little more than ten years ago, I had the honor of bringing before your notice, in connection with Mr. G. F. Matthew, of St. John, a paper upon this subject with special reference to its bearing upon the geology of eastern Maine. I now propose to summarize briefly the results, obtained for the most part in connection with the work of the Geological Survey of Canada, accomplished during the last decade

so far, at least, as these tend to confirm or to modify the views then advanced.

A very considerable portion of the work of the geological staff, in the interval referred to, has been topographical, embracing more exact measurements and delineations of the several formations. The results of this work, as well as the views now entertained as to the geological structure of the region, are roughly represented upon the accompanying map, and more accurately upon a series

of maps now being issued from the office of the geological survey, of which these are proofs.

PRE-SILURIAN.

Beginning with the older formations, we have found no reason to depart from the view first advanced by us, that, beneath the fossiliferous rocks of the St. John or Acadian Group, there exist two, if not three distinct formations, equivalent in part, at least, to the so-called Laurentian and Huronian formations in other parts of Canada. It has been objected that this reference has been based upon the wholly valueless ground of lithological characteristics, and that the strata in question, being destitute of fossils, may even be Silurian; but such objection entirely ignores the fact that, accompanying such differences of lithological characters, there is, at the same time, the most marked evidence of unconformability. A study of the Primordial rocks east of St. John, in 1879, placed this point beyond question, they having been then found by me to occupy irregular troughs in the older PreSilurian rocks, resting sometimes upon one and sometimes upon another of the subdivisions of the latter, crossing their strike obliquely, and having at their base coarse conglomerates made up of the waste of the underlying formations. The latter being thus unquestionably of Pre-Silurian age, it is equally obvious that in their vast thickness, in the markedly different conditions under which their several divisions were accumulated, and finally in the further unconformability indicated between these divisions, they represent a vast interval of time, and are at least as old as the Huronian and portions of the Laurentian system, which in all their physical characters they so nearly resemble. No more marked coördination of distant formations could be desired than is here furnished between the great mass of coarse gneisses at the base of the series, associated with finer gneisses, quartzites, graphitic and serpentinous limestones and dolomites (the probable equivalents of the Hastings' series of Mr. Vennor), and capped by the great volcanic series of the Huronian, with its petrosilicious and felsitic strata, ash-rocks and agglomerates, the whole unconformably traversed by bands of the lowest Cambro-Silurian, and the similar succession observed about Lake Huron and elsewhere.

I have only to add that these Pre-Silurian rocks, as represented upon the maps, are confined wholly to the region of the southern

metamorphic hills, nothing of equivalent age or character having yet been identified in the more central and northern portions of the Province.

It should be added in this connection that in the rocks here assigned to the Huronian, there are as a whole two well-marked divisions, the lower (or Coldbrook group) consisting almost entirely of fine grained felsitie strata, with diorites, amygdaloids and porphyries, and the upper (or Coastal group) of schistose rocks, often talcoid or nacreous, with conglomerates and limestones and holding ores of copper, and that between the two there is not unfrequently evidence of at least a partial unconformability, but in general their relations to each other are much more intimate than are their relations either to the underlying Laurentian, or to the Primordial strata which overlie them.

LOWER SILURIAN.

Apart from the fossiliferous Primordial or Menevian beds of St. John, to which allusion has been made, and of which, since 1870, no less than four parallel belts have been recognized and mapped, reference may here be made to the probable age of some of the great belts of slaty and associated rocks which, in the year referred to, were still involved in obscurity. Of these, one, locally known as the Kingston group, and consisting chiefly of felspathic and hornblendic rocks, but which, from the intimate association therewith of fossiliferous Upper Silurian strata, was thought to belong to the latter formation, has been definitely shown to be older, embracing at the same time two members, of which the lower, as originally described, is Huronian, and the upper, composed largely of slates, Lower Silurian. A second group, which has been the subject of much discussion, and upon which much uncertainty even now exists, is that of the great belt of slate rocks which occupies the interval between the granite hills of the Nerepis range, and the southern margin of the great central coalfield. Among these rocks two prominent divisions may be distinguished, of which the one, and older, is usually of a dark color, and more or less highly crystalline (embracing fine-grained gneisses, micaceous quartzites and mica slates, with staurolites, andalusites and garnets), while the upper is pale green, calcareous and argillaceous, but little altered, and the mica, though abundant, only in the form of scattered scales. No evidence of unconform-.

ability between these two divisions could be detected throughout the extensive area in which they occur, while the metamorphism of the lower beds seemed to be connected with and proportionate to the proximity of the granitic ridges upon and around which they were found to repose. At several points in connection with the lower beds, fossiliferous strata, pronounced by Mr. Billings to occupy an horizon near the junction of the Upper Silurian and Devonian, were found, while in the upper, obscure remains of plants were met with by Mr. Matthew, which in their outline recalled some of the characteristic ferns of the rich Devonian plant beds of St. John. For these reasons, in the paper submitted to the Association at Salem, in 1869, the term Siluro-Devonian was applied to the first described group and that of Devonian to the second, while some speculations based thereon were offered as to the age of the granites and associated slates which form so striking a feature in the geology of the central portion of the Province and of eastern Maine.

Since the date of the meeting referred to, though much attention has been devoted to the subject, no more definite data as to the age of these argillites in southern New Brunswick has been obtained, their highly disturbed condition favoring the occurrence of faults, and their obscure bedding making the study of their stratigraphy extremely difficult; while through far the greater part of the beds there appears to be an entire absence of organic remains. Some observations, however, made during the last two seasons, partly by Mr. Matthew and partly by myself, on the resembling bands of rock which traverse the more central portions of the Province, farther north, have afforded some facts which, though not yet fully worked out, promise to throw some important light upon the question under discussion.

The metamorphic tract bounding the great central triangular coal-basin of the Province on the north, like that to the south, consists essentially of an axis of granitic rock, varying from ten to twelve miles in breadth, which upon either side is flanked by highly disturbed sedimentary beds, of which the great bulk in each case are argillites, of various degrees of coarseness. Between these two sets of flanking strata, some very noticeable differences may be observed: for while, along the southern side of the granitic mass, no rocks are seen other than simple slates and sandstones, in repeated alternations, and these, even within a few yards of the