352 RECOKD OF SCIENCE FOR 1887 AND 1888. 



PosEPNY, F. Ueber die Adiuoleu von Pribram in Biihmeu. Miu. iiud pet. Mittlieihin- 

 gen, 1888, X. Baud, iii. Heft, p. 175. 



Kaisin, Catherine A. Notes ou the Metamorpbic Rocks of South Devou. Qiiar. 

 Jour. Geol. Soc., No. 172, Novembei-, 1887, vol. XLiil, p. 715. 



Ou souie rock speciuieus from Somali Land. Geol. Mag., September, 1888, 



p. 414. 



Describes these rocks as porphyrites, hornblende diabase, granite, gueisses, 

 tnlc schists, epidote schists, qnartzite, grits, sand and lime stones. 



On some rock specimens from Socotra. Geol. Mag., November, 1888, p. 



504. 



ROWE, A. W. On the rocks of Essex Drift. Qnar. Jonr. Geol. Soc, No. 171, August, 

 1888, vol. XLiii, p. 351. 



The rocks were studied with a view, if possible, of ascertaining their original 

 source. They are identified as granite syenite, quartz porphyries, quartz tra- 

 chytes, trachytes, dolerites, granulites, crystalline schists, quai'tzites and quartz 

 rocks, sandstones, limestones, and fragments of silicified woods. 



Rudolph, Fritz. Beitrag zur Petrographie der Anden von Peru und Bolivia. Miu. 

 und pet. Mittheilnugen, ix. Band, iv. u. v. Heft, p. 269 

 The rocks described are andesites of the pyroxene or hornblende varieties. 



RuTLEY, Frank. On Perlitic Felsites, etc. Quar. .Tour. Geol. Soc, No. 176, Novem- 

 ber, 1888, vol. XLiv, p. 740. 



Describes an obscure perlitic structure occurring in certain felsitic rocks of the 

 Herefordshire Beacon; suggests, further, the probability that felsites resulting 

 from the devitrification of obsidian, quartz felsites, aplite, arkose or feldspathic 

 grits may ou decomposition pass into rocks composed mainly of quartz and kaolin 

 and thence by further alteration into epidosite. 



On the rocks of the Malvern Hills. Quar. Geol. Jour. Soc, No. 171, August, 



1888, vol. XLIII, p. 481. 



Sandberger, F. Bemerkuugen fiber den Silbergehalt des Glimmers aus dem 

 Gneisse von Schapbach und des Augits aus d6m Diabase von Andreasberg am 

 Harze. Neues Jahrb. Miu., Geol., etc, 1887, i. Band, erstes Heft, p. 111. 



Sauer, a. Ueber Riebeckit, ein neues Glied der Hornblendegruppe, sowie iiber Neu- 

 bildung von Albit in grauitischen Orthoklasen. Zeitschrift deuts. geol. Gesell., 

 XL. Band, i. Heft, p. 138. 



Schmidt, C. Diabasporphyrite und Melaphyre vom Nordabbang der Schweizer 

 Alpen. Neues Jahib. Min., Geol., etc., 1887, i. Band, erstes Heft, p. 58. 



Describes a diabase porphyrite and meiaphyr presenting certain interesting 

 features. The porphyrite occurs, cutting Eocene .strata in its three typical varie- 

 ties, as a dense, dirty, grayish green, in places dark violet mottled or veined rock 

 carrying small nests of oalcite. In the thin section it is pronouncedly porphyritic, 

 with long, slender plagioclases, which from their small extinction angles are sup- 

 posed to be oligoclase. The groundmass consists of augite and feldspars, some- 

 times grouped in tufls or with a tendency towai'd spherulitic structure. The 

 fiddspars contain inclosures of the amorphous base, often showing a mere vein 

 of feldspar substance. The second variety is of a gray green color, and badly 

 altered, only the feldspars being recognizable while the base has gone over to 

 chloritic material, and granules of opacite, calcite, and chlorite abound. The third 

 variety is a reddish brown dense rock which the microscope shows to consist of a 

 confused aggregate of oligoclase leisteus with interstitial irregularity developed 

 aiigites. The stone therefore presents all the characters of the pre-Tcrtiary por- 

 phyrites, although, as above noted, of post-Eocene age. The meiaphyr is also of 

 interest as containing olivine, which has undergone alteration into a bastite-like 

 substance, here noted for the first time. 



Ueber den sogiiuaunten Taveyannaz-Sandsteiu. Neues Jahrb, Miu., Geol., 



etc, 1888, ij. Band, erstes Heft, p. SO. 



