208 Prof. T. Rupert Jones — On Swiss Jurassic Foraminifera. 



Y. — On The Jurassic Foraminifera of Switzerland : ^ being a 

 Critical Examination of the Species Described and Figured by 

 MM. Zwingli and Kiibler. 



By Professor T. Eupert Jones, F.R.S., F.G.S., 

 of the Eoyal Military and Staff Colleges, Sandhurst. 



THESE Foraminifera were obtained from fifteen zones of the 

 Jurassic strata, between Solothurn, in Switzerland, and the 

 Eichberg, in Baden : three Liassic zones (Black or Lower Jura) ; six 

 in the Brown or Middle Jura; and six in the "White or Upper 

 Jura; beginning with the Turneri-zone of the Lower Lias, and 

 ending with the Pteraspis-zone of Schaffhausen. The Numismalis- 

 marl, Amalthei-clay, Murchison£e-bed, Discoidei-marl, Crenularis- 

 bed, the Coral-limestone, and the Virgulian stage yielded few or no 

 traces of Foraminifera. 



The descriptions and figures of what Dr. Kiibler determines as 

 153 species have had much, care bestowed on them ; but the artificial 

 classification (D'Orbigny's), and a want of rigid comparison and dis- 

 crimination of specific forms, betoken an imperfect knowledge of 

 Foraminifera and a very limited appreciation of the works of pre- 

 vious observers (although some are mentioned), — such as F. A. Eomer 

 (1836), D'Archiac , (1843), Buvignier (1852), Bornemann (1854), 

 Terquem (1858 to 1870), Giimbel (1862), Brady (1867), Schwager 

 (1867), besides D'Orbigny and Strickland, who have treated of 

 Jurassic Foraminifera ; for species and varieties already figured and 

 named are in this work re-named again and again. 



A still larger field for comparison is to be found by taking into view 

 the very similar Microzoa obtained from the Ehsetic and Triassic 

 formations, and figured by Jones and Parker (1860), Giimbel (1861, 

 1869), Schwager (1864, 1870), and Eeuss (1866, 1867, 1868). 



The Swiss specimens are mostly figured as transparent or sub- 

 transparent objects, with, transmitted light; the opaque (porcel- 

 lanous and arenaceous) species are therefore among those that have 

 perspective figures, excepting when they are sufficiently thin, as 

 some MiliolcB and Cornuspirce, to be subtranslucent. 



Hesitating to labour through the very numerous figured varieties 

 of Jurassic Foraminifera industriously embalmed in the plates of 

 this work and those of the authors above mentioned, for the purpose 

 of reducing them to their really few species, it is proposed in this 

 instance to indicate broadly the foraminiferal fauna of each stage, as 

 detailed by Dr. Kiibler, and to offer some remarks on the more 

 striking features, and on the more interesting figures. The names 

 assigned to the figured forms are generally of very little worth ; the 

 generic appellations in many cases will have to be corrected ; but 

 we shall rarely trouble to correct the trivial name ; for, besides the 

 twenty acknowledged recurrent forms, numerous individuals of 

 evidently the same species, and even of the same variety, have been 

 endowed with new names. 



The generic and quasi-generic groups will indicate the relative 



1 Die Foraminiferen des Schweizerischen Jura, etc. B^ the late Pastor H. 

 Zwingli and Dr. J. Kiibler. 4to. pp. 49, with 179 lithographic figures in 4 Plates. 

 (Winterthur, 1870.) 



