lksquereux.] EVIDENCE OF AGE OF LIGNITIC GROUP. 281 



the Permian, vegetable paleontology is able to discern and expose the 

 characters of five divisions of the Carboniferous, each determined by 

 peculiar species of plants, and each also related by analogous or even 

 identical species to both the preceding and the following stages of the 

 formation. 



The records of the paleontology of the Coal-Measures are not less pos- 

 itively referable and less interesting to geology when they bear upon 

 questions of a wider and more general application. To my knowledge 

 no fossil plants from the Coal-Measures of North America were described 

 before 1818 ; in that year Rev. Steinhauer published in the Transactions of 

 the American Philosophical Society* his Fossil reliquia, where he de- 

 scribes and figures, under the generic name of PMtolithus, a few species 

 of Calamites, Lepidodendron, Ulodendron, Artisia, tStigmaria, and Sig- 

 illaria. He mentions, however, in the introduction, that most of the 

 specimens of fossil plants from the Carboniferous represent Filices (ferns). 

 After him Granger, iu 1820, merely mentions a few specimens of coal 

 plants from Zanesville, and refers them to Steinhauer, species.t From 

 that time to 1828, Granger, Cist, and Professor Silliman sent some spec- 

 imens of fossil plants from the Coal Measures of Pennsylvania and Ohio, 

 to Brongniart, who was then preparing the materials for his great coal 

 flora. They represented, as seen from this work, ten species, three of 

 which only were then peculiar to this continent. Iu 1837, Dr. Hil- 

 dreth, of Marietta, so well known by his love and zeal for the study of 

 natural history, and its original researches in some of its branches, de- 

 scribed in the journal of his geological explorations! a number of species 

 whose figures are mostly unrecognizable, and whose references are equally 

 uncertain. The remarks of the author, however, denote long and serious 

 researches into the distribution of the coal-beds and the fossil plants 

 recognized in their connection. For ten years after this nothing is said 

 upon our Carboniferous flora until 1847, when Teschermacher prepared, 

 on the fossil vegetation of North America, a very interesting and valu- 

 able, though too short memoir, published in the Boston Journal of Nat- 

 ural History. § At that time the great paleontological works of Brong- 

 niart, Sternberg, G6ppert,and Uuger were already published, and there- 

 fore the author was able to more clearly analyze and describe the speci- 

 mens which, then, very rare, as he says, were obtained from New Scotia, 

 Rhode Island, and Mansfield, Mass. He is the first to remark upon 

 the affinity of the Carboniferous flora of America to that of Europe, 

 thus opening the way for a greatly-needed comparison between the 

 coal floras of both continents, to which some questions of high interest to 

 geology were then and are still related. Teschermacher mentions in his 

 pamphlet twenty-three species, some, of them described and obscurely 

 figured also, all more or less positively referred to species known from 

 European authors except one. This, he says, has no relation to any 

 known by him. It is left without description and without name. The 

 figure represents a fragmentary specimen of the most beautiful fern of 

 the- Coal-Measures, Odontoptcres Agassizii, .which has never been found 

 but in Rhode Island, and of which splendid specimens are preserved in 

 the Agassiz museum of Cambridge. 



Iu 1850, Prof. H. D. Rogers, then director of the geological survey 

 of Pennsylvania, requested the assistance of a paleontologist for the 

 collection and the study of the fossil plants of the anthracite basin. 



* Vol. 1, new series, p. 265. 



tSilliman's American Jour. Sci., vol. iii. 



t Ibid., January, 1836, and January, 1837, vols, xxix and xxxi. 



§ Vol. v, part 3, June, 1847. 



