208 PETROLOGY. 



sodalite, aiigite, plagioclasc, sanidino, hornblende, olivine, mica, quartz, 

 meionite, vesuvian, sulphur, apatite, titano-ferrite, and hatite. E. T. H. 



Hawes, George W. Contributions from the Sheffield Laboratory of 

 Yale College. — No. xxxvii. The Rocks of the " Chloritic forma- 

 tion " on the Western Border of the New Haven region. Amer. 

 Journ. ser. 3, vol. xii. pp. 122-126. 

 Gives analyses of the trap-like massive metamorphic rocks of this 

 formation (see Dana, p. 131), under the names metadoleryte, meta- 

 diabase, and metamelaphyre, the prefix " meta " indicating the meta- 

 morphic origin of the rock ; and compares them with the corresponding 

 igneous rocks, with which they closely agree. G. A., L. 



Hunt, Dr. T. S. The decayed Gneiss of Hoosac Mountain. Proc. 

 Boston Soc. Nat. Hist. vol. xviii. p. 106. 



. Prof. J. D. Dana on the Alteration of Rocks. Proc. Boston 



Soc. Nat. Hist. vol. xviii. p. 108. 



Kalkowsky, Ernst. Uber griine Schiefer Kiederschlesiens. [Green 

 Slates of L. Silesia.] Min. Mittli. Heft ii. pp. 87-116. 



N. of the valley of the Bober, near Hirschberg, at the foot of the 

 Riesengebirge, is a mountain consisting of clay-slate and of certain 

 rocks, which G. Rose described as ^' green slates." These have been 

 petrographically examined. The principal mass of the tiue green 

 slates consists of orthoclase, hornblende, and iron-ore, wath quartz, 

 plagioclase, calcite, and augite as subordinate constituents. The horn- 

 blende is more or less altered to chlorite and epidote. The '^ chloritic 

 green slates" consist of chlorite (primary, not secondary), quartz, 

 orthoclase, hornblende, and epidote or iron -glance, and microlites. 

 No calcite or augite ; the hornblende is but rarely decomposed. 



P. W.R. 



. [Diabase-porphyry of the Tannebergsihal.] N. Jahrh. 



Heft vi. pp. Q2?>-Q2Q. 



Reply to Yom Rath's strictures on a former communication (see 

 post). Maintains that the Tannebergsthal rock is a diabase-porphyry 

 and not a basalt. P. W. R. 



• . Ueber einige Eruptivgesteine des sachsischen Erzgebirges. 



[Eruptive Rocks of the Saxon Erzgebirge.] N. Jahrh. Heft ii. 



pp. 136-161. 



Describes the syenites of Scharf en stein and the neighbourhood ; a 



compact micaceous diorite, or kersantite, from the Tannebergsthal in 



Voigtland ; and the mica-porphyrite of Eloha. P. W. R. 



Kinahan, G. H. On the Classification and Nomenclature of Rocks. 



Geol. Mag. dec. ii. vol. iii. pp. 114-117. 

 Igneous rocks should be classed according to their age. Nevadite 

 would be a good name for elvanites and passage-rocks between tra- 



