Leonhard and Geinitz Neues Jahrbuch. 273 



Eunge, on tlie Tertiary Eocks (with Brown-coal, Amber, etc.) of 

 the Samland in the Baltic ; Zeuschner, on the Devonian Dolomite 

 between Sandomierz and Chenciny (Poland) ; Blvinn, ou some 

 Pseudomorphs ; Scharf, on Eock-crj^stal, from Carrara ; Credner, 

 on the Native Copper of Lake Superior ; Eoemer's account of the 

 Meeting of German Geologists at Hildesheim, and of some other 

 meetings of Naturalists in Germany and Switzerland ; Von Haver's 

 notice of the summer work of the Austrian Geological Survey, in 

 1868 ; Petersen, on the Basalt and Hydrotrachylyt of Eossdorf, 

 near Darmstadt ; Fuchs, on Vesuvian Lavas ; and numerous letters 

 by good observers and deep thinkers, on original and casual subjects, 

 constitute the chief matter of these three numbers of the Jahrbuch, 

 besides the usual valuable concise notices of current Geological and 

 Mineralogical Literature. There are several illustrations. 



Our German brethren evidently lose nothing of their love of 

 mineralogy and of patient research in the character and history of 

 rock-masses : — subjects that are not widely studied in the British 

 Isles. We see, however, that fossils and geology are not at all 

 neglected, and are well represented in the papers before us. Indeed, 

 we have much to thank the editors and writers of the Jahrbuch for : 

 much new information, carefully worked out, being given in the 

 current parts of this valuable magazine. We hope that its circulation 

 among scientific men in Britain is on the increase. 



II. DESCEiPTioisr OF Parkeria and Loftusia, Two Gigantic Types of 

 Aeenaceous PoEAMiNiFEEA. By Dr. Cahpentee, V.P.E.S., and 

 H. B. BfiADT, F.L.S. 



\_Communicated to the Eoyal Society, April 22nd, 1869.] 



THE authors of this Memoir commence by referring to the separation 

 of the series of Arenaceous Poraminifera from the Imperforate 

 or Porcellanotis, and from the Tubular or Vitreous, first distinctly pro- 

 pounded in Dr. Carpenter's " Introduction to the Study of the Porami- 

 nifera" (1862), on the basis of the special researches of Messrs. Parker 

 and T. Eupert Jones, who had pointed out that whilst there are 

 several genera in some forms of which a cementation of sand-grains 

 into the substance of the calcareous shell is a common occurrence, there 

 are certain genera in which a " test" formed entirely of an aggregation 

 of sand-grains takes the place of a calcareous shell : and that these 

 genera constitute a distinct family, to which important additions might 

 probably be made by further research. 



The propriety of this separation of the Arenacea from the calcareous- 

 shelled Poraminifera has been fully recognized by Prof. Eeuss, the 

 highest Continental authority upon the group ; who had come to accept 

 the principle laid down in Dr. Carpenter's successive Memoirs (Phil. 

 Trans. 1856-1860), that the texture of the shell is a character of funda- 

 mental importance in the classification of this group, iha plan of growth 

 (taken by M. d'Orbigny as his primary character) being of very 

 subordinate value ; and who had, on this basis, independently worked 

 out a systematic arrangement of the entire group, which presents a 



VOL. VI. — NO. LX. 18 



