1 88 PETROGRAPHICAL ABSTRACTS AND REVIEWS 



Schaller, W. T. "Axinit von Californien," Zeitschr. Kryst., 



XLVIII (1910), 148. 



A chemical and crystallographic description. The conclusion is 



reached that axinite is composed of the two isomorphous minerals, 



ferroaxinite, A1 2 B H Ca 2 Fe Si 4 O^, and manganoaxinite, Al 2 B H Ca 2 



Mn Si 4 O l6 . 



Author's Abstract 



Smith, G. F. Herbert. "A Camera-lucida Attachment for the 

 Goniometer," Min. Mag., XV (1910), 388-89. Fig. 1. 

 The camera lucida is used for the representation of "light figures" 

 on imperfect crystals with rounded or striated faces, and for the delinea- 

 tion of small crystals. 



W. T. Schaller 



Winchell, Alexander N. "Use of 'Ophitic' and Related Terms 

 in Petrography," Bull. Geol. Soc. America, XX (1910), 661-67. 



A history of the term ophitic which was introduced in the literature 

 by Michel-Levy in 1877. Originally defined as a texture characterized 

 by feldspars, peculiarly grouped, inclosing more recent diallage or augite, 

 it is at the present time used either in the original sense or applied only 

 to those textures in which the feldspar is inclosed by large anhedra of 

 pyroxene. 



The writer believes the term should be applied to all rocks having 

 plagioclase in lath-shaped crystals which were formed before the ferro- 

 magnesian constituents, and suggests the term "poikilophitic" for that 

 texture which is at once ophitic and poikilitic. 



Alfred C. Lane, "Winchell on Ophitic Texture," Science, XXXII 

 (1910), 513, says: "It seems to me that .... a pyroxenic matrix is 

 an essential part of the idea of the ophites. I am, however, quite willing 

 to give up the idea that the augite must necessarily be altogether in 

 larger grains than the feldspar." 



Albert Johannsen 



