Geology and Mineralogy . 321 



of conifers from Triassic and Jurassic horizons is by Dr. Knowl- 

 ton. The new genus Pinoxylon may be specially mentioned as a 

 Jurassic pine from South Dakota. 



The Triassic flora of North Carolina, as based upon the orig- 

 inal collection of Emmons and most of his types, is the work of 

 Professor Fontaine. The Emmons collection of fossil plants 

 made some fifty years since, and long supposed to have been lost, 

 was recently found in the geological collection of Williams Col- 

 lege by Professor T. Nelson Dale. Their redescription accom- 

 panied by new figures, and made in the light of a knowledge of the 

 several other Triassic plant-bearing horizons since discovered in the 

 United States, is especially satisfactory. The Triassic horizons of 

 North Carolina being among the earliest investigated in this 

 country, represent classic ground. Moreover, from the wooded 

 character of the plant-bearing region, and from the fact that there 

 are few natural products to induce excavation, specimens of this 

 flora are now seldom to be obtained, save from a few localities prin- 

 cipally in Chatham County, where, as at Egypt and Deep River, 

 intermittent coal mining is still being carried on in the same horizons 

 which yielded the important vertebrate fossils Dromatheriiim, and 

 Jficroconodon, and also Mhytklodon rostratus Marsh. The Deep 

 River locality was visited by the reviewer a few years since, but 

 unfortunately the mines and culm heaps were on fire and could 

 not be examined at that time, though being again put in order 

 for further work. 



A rich new Triassic flora from York County, Pennsylvania is 

 of much interest. This was discovered by Mr. A. Wanner, and 

 is in large part figured and described by him, Professor Fontaine 

 also having determined the several forms. While some new 

 plants occur, the essential agreement of this flora with that of 

 North Carolina gives to its description a fundamental value. 



A brief notice of the Triassic flora of Virginia, made by Fon- 

 taine the subject of Monograph VI of the IT. S. Geological Sur- 

 vey publications, is given by Professor Ward, who notes the 

 agreement between this and the Triassic flora of Lunz in Austria 

 later studied by Stur and referred by him to the Keuper. 



A characteristic Jurassic flora from Oroville, California, is 

 described and illustrated by Professor Fontaine. 



The Jurassic cycadean trunks from Carbon County, Wyoming, 

 forming the new genus Cycadetta with twenty species, are 

 described by Professor Ward. A review of his preliminary 

 description of these cycads was given by the present reviewer 

 in this Journal for April, 1900, pp. 383-387, and need not be 

 repeated here. The 104 plates now devoted to the illustration of 

 these fine fossils forms the principal feature of the present 

 volume, as well as a most interesting addition to the series of 

 plates showing various forms of isolated cycadaceous leaves so 

 prominent in the several Triassic and Jurassic floras mentioned 

 above. 



In addition to these Wyoming cycads Professor Ward also 



