PETROLOGF. 211 



garnets, ilmenite, and, in some cases, an altered diallage. Opaline 

 silica and calcite are often present as minerals of secondary origin. The 

 altered rock is traversed by veins of diorite ; and the diamonds appear 

 to be most abundant in the neighbourhood of these veins. The paper 

 contains analyses of the principal rock-constituents, and descriptions of 

 specimens from Bulfontein, Du Toit's Pan, and the New Eush. 



F. W. R. 

 Metinier, Stan. Presence do la zircosyenite aux iles Canaries. 

 [Zircosyenite from the Canary Islands.] Compt. llcnd. t. Ixxix. 

 pp. 594, 595. 

 Notices the presence of zircosyenites, identical with those of Scan- 

 dinavia, at Fortaventure, in the Canary Islands. 



MoHL, H. Die Basalte der rauhen Alb, mikroskopisch untersucht 

 uud bcschrieben. Jahresheft Yer. Naturk. "Wiirttemberg, p. 33, 

 with plate. [Noticed in N. Jahrb. Heft 7, pp. 745-747.] 

 Description of microscopic structure of the basalts of the Swabian 

 Alb. All of them are nepheline-basalts. The olivine is remarkably 

 fresh even in rocks which have been much altered ; some of the basalts 

 are rich in apatite ; in others the nepheline and vitreous base are con- 

 verted into carbonate of magnesia and a zeolite, regarded as chabasite. 



F. W. R. 



. Mikromineralogischo Mittheilungen. Erste Fortsetzung. N. 



Jahrb. Heft 7, pp. 675-710, Heft 8, pp. 785-804, with plate. 

 Describes microscopic structure of several newly discovered German 

 haiiyne-basalts ; trachyte-pitchstone, quartz-trachyte lava, and sani- 

 dine-trachyte lava from East Java; sanidine-trachytes from Flores 

 and Aden ; trachytes from Central Java ; diabase from Eorneo ; bronzite 

 from Borneo ; and minette from Saxony. Also describes sandstone and 

 limestone altered by basalt, from Weissholz, near Liitgeneder. 



F. W. R. 



. IJeber die mineralogische Constitution und Eintheiluug der 



Phonolithe. N. Jahrb. Heft i. pp. 38-45. 

 The results of the study of 624 microscopic sections of phonolite. 

 Describes the mineralogical constitution of typical sections, and 

 suggests the following classification — Noscan-phonolite (2 varieties), 

 Haiiyne-phonolite (2 varieties), Nepheline-phonolite, Nepheline-glass 

 phonolite, and Mica-phonolite. F. W. R. 



. ZusammensteUung, mikroskopisch e XJntersuchung und Be- 



Bchreibung einer Sammlung typischer Baaalte. [Microscopic struc- 

 ture &c. of Basalts.] N. Jahrb. Heft 9, pp. 897-942, with 

 plate. 

 A descriptive catalogue of a collection of 30 specimens of typical 

 basalts, selected by the author and prepared as microscopic objects by 

 Fuess of Berlin. Two groups are recognized — vitreous basalts and 

 true basalts: the latter class is subdivided into 6 groups — magma- 

 basalts, felspar-basalts, nepheline-basalts, leucito-basalts, haiiyne- 

 basalts, and mica-basalts. F. W. R. 



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