4 PROCEEDINGS OF MADISON MEETING. 



flora also, like that of the Erian, prevails from the north pole to the equator, and 

 with some modification in the southern hemisphere. We have here also three 

 well marked sub-floras. The oldest is characterized by lepidodendra, with im- 

 perfectly developed exogenous woody zone and short leaves of the type of -L. 

 velthemianum, and by cyclopterid ferns of the type which I have named Aneimites. 

 The Horton series of Nova Scotia, the lower or bastard Coal Measures of the 

 Southern states, and the Tweedian series of England and Scotland exemphfy this 

 flora, which is markedly distinct from that of the upper Erian below and that of 

 the Millstone Grit and productive coal measures above. The central group exem- 

 plifies the culmination of the well known coal formation flora, on which no special 

 remark need be made. Above this the Carboniferous flora dwindles into that of 

 the Permian, described by Fontaine in the south and by Mr Bain and myself in 

 Prince Edward island. The genus Tylodendron is one of its peculiar forms, as well 

 as certain species of calamites, ferns and asterophyllites. 



The older Mesozoic flora is quite distinct from that of the Carboniferous on the 

 one hand and that of the middle Cretaceous on the other. Its subdivisions are 

 not so well marked or so well ascertained as those of the Carboniferous, but there 

 are certainly distinct Triassic, Jurassic and lower Cretaceous forms, quite suffi- 

 cient for paleontologic distinction. 



In the middle and upper Cretaceous and the Tertiary there has been much con- 

 fasion, owing to want of stratigraphic distinctness of the beds holding the fossils. 

 This difficulty is, however, rapidly being removed, and Starkie Gardner, in En- 

 gland, and Ward, in America, have been successfully laboring in this, while we 

 have been doinc our share in Canada. In North America, at least, there is now 

 no difficulty in distinguishing a lower, middle and upper Cretaceous flora, besides 

 that of the Laramie, which is more nearly related to the lower Eocene than to that 

 of the Cretaceous, that of the Miocene, and that of the Pliocene and Pleistocene. 

 The distinctness and yet similarities of these successive floras, their growing assim- 

 ilation to those of the modern period, and the vicissitudes of physical geography 

 and climate which they indicate are among the most remarkable facts of modern 

 geology ; and it is not saying too much to affirm that, in so far as climatal condi- 

 tions are concerned, the evidence of fossil plants has done more than that of ani- 

 mals to elucidate these vicissitudes of the earth's later history, and that it is des- 

 tined in the near future to do so still more. On this part of the subject, however, 

 I do not propose to enter at present. It is one raising a great variety of difficult 

 questions resj)ecting the alternations of warm and cold climates in the northern 

 hemisphere, and I hope to make it the subject of an address for our winter meet- 

 ing- _ 



This country has lost within a short time two distinguished paleobotanists : 

 first Lesquereux and then Newberry — losses hard to be supplied. It is, however, 

 gratifying to know that there are younger men ably following in their steps. The 

 Geological Survey of the United States has just published, under the judicious 

 editorship of Professor Knowlton, Lesquereux's last work on that most interesting 

 flora of the Dakota group, which in Cenomanian times extended itself over North 

 America and as far as Greenland; and for the flrst time established on our conti- 

 nent, and this in a grand and noble form, the undisputed reign of the dicotyledo- 

 nous trees. To this report Lesquereux has appended an analysis of the Cretaceous 

 floras, embodying the results of his long experience, and tracing the fortunes of the 

 several genera, so far as known, from their earliest appearance to the modern time, 



