218 PETllOLOGY. 



of tho siliceous oemcnting material ; aud explains the geological position 

 of the rock. F. W. R. 



Wiik, F. J. Mineralogiska och petrografiska meddelanden. [Mine- 

 ralogical and Petrographical notes.] Ofv. Fliislca Vet. Soc. Fork. 

 Bd. xvii. pp. 7-50. 

 Gives a description of the physical, optical, and microscopical cha- 

 racters of the following Pinland minerals and rocks, viz. : — Triplite, 

 mctaxoite, pikroflnite, marmolite, skotiolite, hisingerite, ripidolite, 

 olivine-diabase (pseudo-hyperite), sardovalite, olivine-gabbro (2 locali- 

 ties), gabbro (2 localities), diabase, diabase-aphanite, uralite-porphyry, 

 diorito (2 localities), and diorite-jiorphyry. E. E. 



Winther, A., and W. Will. IJeber den Basalt des SchifFenbergcs. 

 Ber. oberhess. Ges. t. xv. pp. 33-44. 



Tho Schiffenberg basalt is composed of augite, olivine, magnetic and 

 titaniferous iron, with other minerals. Many analyses are given. 



W. H. D. 



Zirkel, Prof. Ferdinand. Microscopical Petrography. Bep. U. S. 

 Geot. Exj)l. 4:0th Par. vol. vi. pp. 298 ; 12 pis. 4to. Washingto?i. 



The following rocks are described : — Crystalline schists and related 

 rocks ; granite and granite-porphyry ; felsite-porphyry and syenite ; 

 diorite, hornblende-porphyry, diabase, melaphyre, and gabbro ; propy- 

 lite, quartz-p ropy lite, hornblende-andesite, dacite ; trachyte and rhyo- 

 lite ; basalts, w4th augite, andesite, leucite rocks, and clastic rocks. The 

 work is the result of the examination of a large collection of rocks 

 made by the Survey. More than 2500 specimens have been examined 

 microscopically. Holds that the eru2:)tions in the Tertiary period in 

 this district took place in the following order — Propylite, andesite, 

 trachyte, rhyolite, basalt, — an order established elsewhere by Eichthofen. 

 The schists consist of gneiss, micaceous and hornblendic, hornblende- 

 rock (containing few other minerals), quartzites, mica-slate, garnet- 

 rock, paragonite-schist with disthene, clay-slate, and crystalline marble. 

 The eruptive granites are supposed to be Jurassic ; others are meta- 

 morphic, T. G. B. 



. [On some American Eocks.] Zeitsch. deutscJi. geol. Ges. 



Bd. xxviii. Heft 3, pp. 630, 631. 



Note on rock specimens from the 40th parallel, United States, com- 

 prising archaic schists with liquid CO^ cavities, granites, diorites, &c. 

 Comparisons between European augite-andesites and American basalts 

 are added. E. B. T. 



[Variohte.] N. Jahrh. Heft iii. pp. 279, 280. 



Eex^ly to Giimbel's strictures on the writer's remarks on the variolite 

 of Bemeck in the Pichtelgebirge. Denies that this variolite is petro- 

 logically related to diabase. Admits the term perldiahase on the 

 understanding that it is not to indicate a perJitic diabase. F. W. E. 



