Geology and Natural History. 85 



About one-half of the book is devoted to the description of the 

 more important mineral species. The descriptions have been 

 very carefully written and give much information which will be 

 welcomed by all advanced students of mineralogy. A note- 

 worthy feature of the book is the large number of excellent, 

 shaded, half-tone illustrations of crystals and crystal aggregates, 

 skilfully drawn by the author's sister, Miss J. Miers. The ordi- 

 nary outline crystal figures are also well executed, and the text 

 is fully illustrated, there being in all 666 figures and two colored 

 plates. 



At the close of the volume there are useful lists of the princi- 

 pal minerals, tabulated according to the chemical classification ; 

 according to their mean refractive index in sodium light ; birefrin- 

 gence ; divergence of the optical axes, 2E, 2V, and 2H; lastly, 

 according to specific gravity. The volume is well printed on 

 excellent quality of paper, and in this respect may well serve as a 

 model for books of its kind. s. l. p. 



5. Zur Fossilen Flora der Polarlander ; von A. G. Nathorst. 

 Erster Teil. Dritte Lieferung: Zur Oberdevonisehen Flora der 

 Btiren-Insel (mit 14 Tafeln). Kongl. Svenska Vetenskaps-Aka- 

 demiens Handlingar, Bandet 36, No. 3. Stockholm, 1902. — The 

 great age of the plants described in this contribution gives it an 

 especial interest. The Bear Island lies about midway between 

 the North Cape and Spitzbergen. And certain fossil plants de- 

 scribed from it by Heer thirty years ago were considered as being 

 of Carboniferous age. Nathorst, however, finds from both faunal 

 and floral evidences that the several beds from which he has in 

 the past few years secured upwards of thirty species of Filicales, 

 Sphenophyllales, Calamariales, and Lycopodiales, are Upper Devo- 

 nian. He says : " One needs but to inspect briefly the florula 

 of the Bear Island to see that vascular plants must have existed 

 for an exceedingly long period previous to Upper Devonian 

 time." g. e. w. 



6. Beitrage zur Kenntniss einiger Mesozoischen Cyeadophyten 

 (mit 3 Tafeln und 1 Textfigur) ; von A. G. Nathorst. Kongl. 

 Svenska Yetenskaps-Akademiens Handlingar, Bandet 36, No. 4. 

 Stockholm, 1902. — In the foregoing paper Nathorst describes an 

 exceedingly interesting series of cycadaceous fructifications, in 

 part accompanied by stems or leaves, all of which are of late 

 Triassic age. That very important fossil Williamsonia angnsti- 

 folia Nathorst ( = Anomozamites minor) from the Upper Keuper 

 sandstones of Hor in Skone is redescribed from additional speci- 

 mens, and many figures are given. This plant has a slender, 

 freely branching stem, Nilssonia-like leaves, and fructifications 

 that are obviously Bennettitean. It is highly suggestive of the 

 wide range of form that the Bennettites-like plants must have 

 exhibited. Among the specimens figured and described there are 

 some unmistakable ovulate strobili of the Williamsonia and 

 JBennettites type. As compared with either of these genera there 

 are no fundamental differences apparent in these fruits. Like- 



