Notices of Memoirs — Br. Riist on RacUolaria. 513 



and Lower Culm strata from porfions of the granitic areas in question, 

 but these must be dealt with subsequently. There is, however, oue 

 important point to which the writer desires to draw attention — that 

 is, the almost certain fact that the Devonian and Lower Culm 

 strata had been previously disturbed and folded by great earth-crust- 

 movements before the protrusion of the granite. The arrangement 

 and disposition of the strata in relation to the granite certainly 

 favour this conclusion. The great plications and the cleavage of the 

 strata had at least in greater part, if not in whole, been completed 

 before the eruption of the granite had taken place, and also before 

 the conglomerate series of South Devon had been deposited, which 

 latter occurrence, however, the author believes was subsequent to the 

 eruption of the granite. It is extremely probable that these highly 

 acid cores which now represent the granite never were the stumps 

 or roots of great volcanic cones, in the correct sense of the term, 

 as suggested by the late Mr. R. N. Worth, ^ from which proceeded 

 highly basic lavas, but rather that they were the feeders or more 

 central portions of extrusions, parts of which came to the surface 

 as trachyte, forming great dome-like masses after the manner of the 

 Puy de Dome, near Clermont Ferrand, in Central France. 



In conclusion, the author is aware that the evidences here brought 

 forward to sustain his views as to the age and origin of the granite 

 of Dartmoor are not absolutely conclusive ; but when compared with 

 the opinions already held they seem at all events worthy of con- 

 sideration and discussion. 



I. — Neue Beitrage zur Kenntniss der fossilen Radiolarien 

 Aus Gesteinen des Jura und dek Kreidb, von Dr. Eust. 

 Palseontographica, Band xlv (1898). 4to ; pp. 67, pis. i-xix. 



New Contributions to the Knowledge of the Fossil Radio- 

 LARiA from the Jurassic AND Cretaceous Eocks. By Dr. EiJST. 



SINCE the completion of his important work on the Paleozoic 

 Eadiolaria, Dr. Eiist has been revising his earlier monographs 

 on those from the Jurassic and Cretaceous strata. Struck by the 

 close resemblance of the forms in the Upper Jurassic Aptychus-beds 

 of Cittiglio, near Laveno, from which 79 new species were described 

 and figured by Professor Parona- some years since, to those which 

 he himself^ had described from the Lower Neocomian beds at 

 Gardenazza near St. Cassian, the Aptychus shales near Urschlau, 

 and from Kren, and the Tithonian jaspers of the Tyrol and West 

 Switzerland, Dr. Eiist prepared some hundreds of microscopic 

 sections of the nodules of siliceous limestone from Cittiglio, and in 

 these he has discovered no fewer than 212 new species, which, with 



1 Quart. Journ. Geol. Soc, vol. xlv, p. 398, etc. 



2 BoUettiuo delta Soc. geol. italiana, vol. ix, fasc. 1 (1890). 

 ^ PalEeontographica, Bd. xxxi (1885) ; Bd. xxsiv (1887-8). 



DECADE IV. VOL. V. — ^NO. XI. 33 



