212 PETROLOGY. 



Dagesfors, Sweden. Names the principal genera of microscopic organ- 

 isms which these deposits contain. F. W 11. 



Pond, J. A. Analyses of a Few of the Fire-Clays of the Province of 



Auckland. Trans. N. Zealand Inst. vol. viii. p. 348. 

 Six analyses, with remarks. 



Poussin, Ch. de la V., and A. Renard. Memoire snr les Caracteres 



Miner alogiques et Stratigraphiqnes des Roches dites Plutoniennes 



de la Belgique et le I'Ardenne Frangaise. [Mineralogical Characters 



of the so-called Plutonic Rocks of Belgium and the Ardennes.] 



Pp. 264 ; 9 plates. 4to. 



Describe the petrography and microscopic structure of the quartzose 



diorite of Quenast and Champ St.-Yeron, of the gabbro of Hozemont 



and Grand Pre, of the quartz-porphyry of Spa, and of a number of rocks 



with a general resemblance to felstones, more or less schistose in 



structure, named " porphyroids." These rocks are shown to be of 



clastic origin, though often very greatly altered. Details of their mode 



of occurrence and of their microscopic structure are given, as well as 



those of some hornblendic rocks of like origin. T. G. B. 



, . Ueber die Feldspath- und Hornblende-Gesteine der 



franzosischen Ardennen. [Felspar- and Hornblende-rocks of Ar- 

 dennes.] Zeitsch. deutscJi. geol. Ges. Bd. xxviii. Heft 4, pp. 750- 

 774, pi. xi. (map) and 6 cuts. 



Partly a translation from the original memoir, with a supplement in 

 answer to certain criticisms by Rothpletz. 



Rath, G. vom. Das Syenitgebirge von Ditro und das Trachytgebirge 

 Hargitta. [Syenitic Mountains of Ditro, and the Trachytic Moun- 

 tains of Hargitta, near Biidosch, E. Transylvania ; with Observa- 

 tions on the Auriferous Districts of Yorospatale and Nagj^ag.] 

 Pp. 55. 8vo. Bonn. 

 Describes Miascite (nepheline-syenite) and Ditroite (sodalite-sy- 

 enite). Gives analyses of andesite and particulars of the auriferous 

 rocks. W. H. D. 

 . [Basalt-dyke in the Saxon Yoigtland.] N. Jahrb. Heft iv. 



pp. 400-402. 

 Reply to Kalkowsky's criticisms (see p. 208). Holds that the rock 

 which occurs as a dyke near Tannenbergsthal is a basalt modified by 

 contact with the neighbouring rocks, and not a diabase-porphyry. 



F. W. R. 

 [The Topaz-rock of Schneckenstein.] N. Jahrb. Heft viii. 



pp. 855, 856. 



Describes a visit to the quarries in this rock, and refers again to the 

 Tannenbergsthal rock. 



Renard, A. Sur la structure et la composition mineralogique du 

 coticule, et sur ses rapports avec le phyllade oligistifere. [Structure 



