ON THE CAMBRIAN FAUNAS OF NORTH AMERICA.

PRELIMINARY STUDIES.

BY CHARLES D. WALCOTT.

REVIEW OF THE FAUNA OF THE SAINT JOHN FORMATION CONTAINED IN THE HARTT COLLECTION AT CORNELL UNIVERSITY.'

During the summer of 1877 the writer visited Saint John, N. B., and taking advantage of information kindly given by Mr. G. F. Mat

'The term "Saint John Group" was first proposed in 1865 (Observations on the Geology of Southern New Brunswick, Fredericton, N. B., pp. 26–32) by Messrs. L. W. Bailey, G. F. Matthew, and C. F. Hartt. Subsequently, Mr. J. W. Dawson (Acad. Geol., 2nd ed., p. 638, 1868) proposed to substitute the name Acadian for the same formation. He says: "This formation has as yet been known as the Saint John Group; but I think this name unsuitable, both on account of the number of places known as Saint John, and on account of the variety of formations occurring near Saint John, in New Brunswick, and would therefore propose for the group now under consideration, characterized by Paradoxides, Conocephalites, &c., and the oldest known member of the Paleozoic of America, the name Acadian Group, by which I hope it will be known to geologists in whatever part of America it may be recognized."

The geographic area bearing the name of Acadia is defined by Mr. Dawson (Ibid., p. 5) as "distinguished from all the neighboring parts of America by the enormous and remarkable development within it of rocks of the Carboniferous and Triassic systems." This certainly renders the name inapplicable as a substitute for a well-defined local name previously given to the formation under consideration.

Saint John, N. B., is quite as well known as Trenton, New York, from which the well-known Trenton limestone is named. We would not give as a reason for changing that name that other towns in the United States bear the name of Trenton.

Mr. Matthew, in speaking of the Saint John formation, says (Trans. Roy. Soc. Canada, vol. i, p. 87, 1882): "From these repor s and from the map it will be seen that the strata of the Saint John Group fill a number of narrow, trough-like basins lying between the Bay of Fundy and the central Carboniferous area of New Brunswick. Of these basins, that on which the city of Saint John is situated is the most important, and it is here, also that the life of the period can be studied to the best advantage. The Saint John basin lies diagonally across the ridges of Huronian rock that are found in the eastern part of Saint John County; and touches the ridge of Laurentian rocks that divides this county from Kings."

I cannot but think that if we pay attention to the law of priority, justice to the original discoverers of this group requires that the name of Saint John formation should be used as expressing the division of the Lower Cambrian, so well developed at Saint John.

The name Saint John or Acadian cannot well be applied to the Newfoundland or Braintree Paradoxides beds. The three localities present local differences and characters which, while permitting their being united under the general term Lower Cambrian, render it necessary to use a local name for the formation in each of the widelyseparated localities.

thew, obtained a large collection of fossils from the typical localities at Saint John, Ratcliff's Millstream, and Portland, from which Mr. C. F. Hartt procured the collection described by him in the second edition of Dawson's Acadian Geology. Subsequently when working over the material, it was with great difficulty that more than the common species could be identified from the descriptions, and few figures given in the Acadian Geology. The writer at that time formed the plan of illustrating the original typical Hartt collection and also the entire fauna, as far as possible. His own collection afterward went to the Museum of Comparative Zoölogy at Cambridge, Mass., and it was not until the latter part of 1883 that the trustees of Cornell University came in possession of the Hartt collection. Through the co-operation of Mr. H. S. Williams, paleontologist of the university, the loan of the collection was obtained for the purpose of illustrating the type specimens and such other material as would add to our knowledge of the fauna. In writing to Mr. L. W. Bailey, of Fredericton, N. B., and Mr. G. F. Matthew, to secure their co-operation, the writer learned for the first time that Mr. Matthew was engaged on a monograph of the fauna of the Saint John formation. The plan of illustrating the entire fauna was at once changed so as to include only the Hartt collection, and Mr. Matthew was requested to propose specific names for the new species with the exception of one form with which the writer wished to connect the names of Mr. Hartt and Mr. Matthew, the two gentlemen who first gave to the scientific world a definite knowledge of this early Cambrian group. Mr. Matthew kindly accepted this proposal, and the writer proceeded with the work, using only the material contained in the Hartt collection.

Mr. Matthew's valuable paper on the genus Paradoxides of the Saint John Group, has already appeared (Trans. Roy. Soc. Canada, vol. i, 1882), and from it we learn that he recognizes three well-defined species and six varieties: Paradoxides lamellatus, Hartt; P. lamellatus, var. Loricatus, Matthew; P. Acadicus, Matthew; P. Eteminicus, Matthew; P. Eteminicus, vars. suricoides, breviatus, Quacoensis, Malicitus and pontificalis.

In the Hartt collection we find as the types of P. lamellatus a portion of the head of two specimens. The species appears to be of rare occurrence. Mr. Matthew illustrates but a fragment of the head of a specimen which he considers as indicating a variety of P. lamellatus.

Two other species occur in the collection that were not named by Mr. Hartt. P. Acadicus, Matt., is represented by the larger portion of an entire individual, and P. Eteminicus, Matt., by numerous fragments of the head. The P. Micmac, figured by Mr. Dawson (Acad. Geol. 2d ed., p. 657), is not represented in the collection, and Mr. Matthew writes me that the original specimens were destroyed in the great Saint John fire of 1877, and that he is unable to identify the species. The figure is a restoration, and no description accompanies it; on this account it ap

pears best to drop the name from the list of species composing the Saint John fauna, as an undefined and undetermined species.

In reviewing the fauna as shown in the Hartt collection, we find the Echinodermata represented by single detached plates of one species, Eocystites primævus, Bill. A somewhat similar form occurs in the Menevian group of Wales, under the name of Protocystites Menevensis, Hicks.

Among the Brachiopods, Lingula? Dawsoni, Matt., Acrothele Matthewi, Hartt, Obolella transversa, Hartt., Obolella, sp., Orthis Billingsi, Hartt, and Orthis, sp. ?, show how rich and varied this class must have been at the time of the deposition of the Saint John formation.

The new type representing the Gasteropoda, Harttia Matthewi, is of special interest owing to its being the oldest representative of the class known on the North American continent, and the section of the family which it approaches most nearly is doubtfully known, if at all, below the Tertiary system. The species Palæacmea? Acadica, is as yet doubtfully referred to the gasteropoda.

Of the Pteropoda there are three species, Hyolithes Acadica, Hartt, H. Danianus, Matt., and H. Micmac, Matt. The former is not unlike H. primordialis, Hall (Sixteenth Ann. Rep. N. Y. State Cab. Nat. Hist., p. 135), of the Potsdam sandstone of Wisconsin, and the second approaches H. cinctus, Barr. (Syst. Sil. Bohême, vol. iii, p. 78), of the Cambrian of Bohemia.

The class Poecilopoda, order Trilobita, is the dominant type in the Saint John fauna, as it is in all the known Cambrian faunas, and is represented by Agnostus Acadievs, Hartt; Microdiscus Dawsoni, Hartt, M. punctatus, Hartt; Paradoxides lamellatus, Hartt, P. Acadicus, Matt., P. Eteminicus, Matt.; and varieties suricoides, breviatus, Malicitus, pontificalis and Quacoensis; Conocoryphe Matthewi, Hartt, C. elegans, Hartt, C. Walcotti, Matt., C. (Salteria) Baileyi, Hartt; Ptychoparia Robbi, Hartt, P. Quangondiana, Hartt, and variety Aurora; P. quadrata, Hartt, P. Orestes, Hartt, and varie y Thersites, and P. tener, Hartt.

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Mr. Hartt, described, in addition to these, Conocephalites gemini-spinosus Conocoryphe Matthewi; Conocephalites formosus Ptychoparia Robbi; Conocephalites Aurora Ptychoparia Ouangondiana, variety Aurora; Conocephalites Halli Ptychoparia Orestes; Conocephalites Thersites = Ptychoparia Orestes, variety Thersites; Conocephalites neglectus = Ptychoparia tener. It is with great reluctance that I reduce the above-named species to varieties and synonyms of other species, and it was not until after many comparisons and a study of all the material in the collection that it was done. Good figures are given of the types of each of Mr. Hartt's species, and the student has before him the original descriptions, so that he can judge for himself and not entirely rely upon the writer to form his opinion of the value of the species.

* The Cambrian system, as referred to in this paper, is that series of strata charac terized by the first fauna of Barrande.

In review we find 14 genera, 26 species, and 6 varieties, distributed as follows: Echinodermata, 1 genus, 1 species; Brachiopoda, 5 genera, 7 species; Gasteropoda, 1 genus, 1 species; Pteropoda, 1 genus, 3 species; Trilobita, 6 genera, 14 species, 6 varieties.

That Mr. Matthew's researches will increase this number of species there is little doubt, and it is not improbable that some of the species of Mr. Hartt which are placed in this paper as synonyms of some others may yet prove to be distinct.

Mr. Matthew states (Trans. Roy. Soc. Canada, vol. i, p. 89) that among the collections made by the Canadian Geological Survey in New Brunswick, Mr. Billings recognized fragments of the genera Elliptocephalus and Salterella, and the remains of two species of Hyolithes. "Besides these, there are the supposed plant remains, Palæophycus, Eophyton, etc., of the higher divisions of the Saint John Group."

While studying the species, the question of their correct generic reference came up, and a number of species of three different genera were found to be arranged under the genus Conocephalites, a genus that, with the greatest respect for the opinion of its author and his work, I cannot see the way clear to accept. The reasons for this will be found under remarks on the genus Ptychoparia. The new subgenus Salteria may be of doubtful subgeneric value, but with the characters of C. (Salteria) venulosa, Salter, before us, a subgeneric group, appears to be indicated.

The fauna of the Saint John Group has been most happily compared by authors with that of the Paradoxides fauna of Bohemia, Wales, and Sweden. The resemblance to that of the Menevian of Wales is very striking, and the relationship so close that we are in doubt if there are not more identical species than Microdiscus punctatus in the two faunas.

The more closely related species are: