Reviews — Dr. Ruest — Jurassic Radiolaria. 79 



The fauna and flora of these Tertiary deposits are very carefully 

 described and most admirably illustrated in the accompanying atlas 

 of plates ; the figures have been drawn by the author's own hand. 

 Numerous new species of freshwater mollusca and of foraminifera 

 are introduced. 



The second memoir consists of a detailed description of a section 

 of diluvial or Post-Tertiary sands and marls exposed in the Rhine 

 valley at Hangenbieten, a short distance from Strassburg. The total 

 thickness of the deposits is about 15 metres. The uppermost stratum 

 is a typical non-stratified Loess, containing land-shells exclusively, 

 which the author regards as Post- Glacial. Beneath this is a Loess 

 of nearly the same petrographical character as the bed above, but 

 containing freshwater as well as land-shells. Next below is a reddish 

 sand — known as renovated Vogesen sand — which contains 17 species 

 of land and 13 of freshwater shells, and in places remains of Mam- 

 moth and Reindeer. The author places this, and the Loess above it, 

 as probably of Glacial age. Under the Vogesen sand are concre- 

 tionary marls, in which the freshwater molluscs are more numerous 

 than the land forms, and these are succeeded below by fluviatile 

 sands in which 79 species of molluscs (48 land and 31 freshwater) 

 have been discovered. Four of these are entirely extinct species, and 

 many others have altogether disappeared from the district. A still 

 lower bed of sand with but few fossils in it forms the base of the 

 section. These lower beds are regarded as of Interglacial age. 



The author furnishes a table in which a comparison is made of the 

 fauna of the Hangenbieten section with that now existing in Elsace 

 and the district of the Upper Rhine, and with that of Mosbach near 

 Biebrich and of Mauer near Heidelberg. Descriptions are given of 

 some new forms, and all the species are shown with remarkable 

 clearness in the appended photographic plates. G. J. H. 



II. — Beitrage zur Kenntniss der fossilen Radiolarien atjs 

 Gesteinen des Jura. Von Dr. Rust, in Freiburg I /B. Pakeon- 

 tographica, Band xxxi. Mit Tafel i. — xx. (Cassel, 1885.) 



Contributions to the Knowledge of Fossil Radiolaria from 

 Rocks of the Jura. By Dr. Ruest, of Freiburg. Palaeonto- 

 graphica, vol. xxxi. pp. 51, with 20 plates. 



WITH the exception of a few species of Radiolarians from the 

 Upper Chalk of North Germany described by Zittel, and 18 

 species from the Lower Lias of the Tyrol, which Dunikowski has 

 named and figured, 1 scarcely anything has hitherto been known of 

 fossil Radiolaria from strata older the Tertiary, and these minute 

 siliceous organisms have been regarded as forming but an insignifi- 

 cant part of the fauna of the older rocks. The present memoir, in 

 which 234 different species of Radiolaria belonging to 76 genera, are 

 described from Cretaceous and Jurassic strata, furnishes good evidence 



1 Dr. G. C. "Wallich has lately called attention to the occurrence of Eadiolarians in 

 the cavities of flints from the Upper Chalk of Surrey, but they have not yet been 

 described. Ann. and Mag. Nat. Hist. 5th ser. vol. xii. p. 52, 1883. 



