44. 



PROTOZOA— EHIZOPODA 



PHTLUM I 



instances (Miocene of Barbados, Oran, Sicily) have 

 unaltered, and still consist of amori^hous silica. I 

 has usually become dissipated in the matrix, being 

 iron, or some colouring agent ; in other cases the 



Pio. 44. 



Recent and Tertiary Nasselarians : A, Podocyrtis schomburgki Ehrbg. 

 Tertiary marl; Barbados. B, Cyrtocalpis amphora Haeclv. Recent; 

 Messina. C, ISothnjocainpe liexathahvniia Haeck. Recent; Mediterranean. 

 D, Pdalospyris fuveolata Mhrhg. Tertiary marl ; Barbados. 



the skeletons been preserved 

 n the older rocks the silica 

 replaced by lime carbonate, 

 quartz has become crypto- 

 crystalline, or replaced by 

 a calcite pseudomorph. 



The Cambrian GrifFel- 

 schiefer of Sonneberg in 

 Thuringia contain poorly 

 ■ preserved Sphaeroidea ; the 

 usually dark, though some- 

 times red or light-coloured 

 Ordovician strata of Lan- 

 genstriegis in Saxony, and 

 of Rehau and Steben in 

 Franconia, the red jasper 

 of Abington, Scotland, 

 and the Ordovician sili- 

 ceous rocks of Cabrieres 

 in Languedoc, are more or 



less rich in Radiolarian 

 remains belonging exclusively to the Spumellaria (Fig. H, A, B). 



From the Devonian jasper of Siberia, the siliceous schists of Hesse and 

 Nassau, and the manganiferous quartzite of Elbingerode in the Harz, and 

 other places, Riist has described forty-six Spumellarian species and seventeen 

 Nasselarian (Cyrtoidea). The Lower Carboniferous quartzites, phyllites, 

 adinole and jaspers from the Harz (Culm formation), Ural district and Sicily 

 have yielded 155 species, of which thirty-six belong to the Nasselaria. In 

 general the Paleozoic Kadiolarians are remarkable for their relatively large 

 size and excellent preservation. 



The Triassic appears to be destitute of Radiolarians except in the Alps, 

 where they are abun- 



^ AT* 



D 



E 



dant in the hornstone 

 and siliceous lime- 

 stone of the Buchen- 

 stein beds of Hungary, 

 and occur less fre- 

 quently in the Rei- 

 fling limestones, in 

 the Wengen beds of 

 Storzic in Carniola, 

 in the marls of St. 

 Cassian, and in the 

 siliceous limestone of 

 the Rothelstein, near Aussee, etc. They are usually associated here with 

 the remains of Sponges and Foraminifera. In the silicified coprolites of 

 the Lias, found at Ilsede, Hanover, Radiolarians are very common; they 

 are somewhat less frequent in the limestones of the Lower Lias on the 

 Schafberg in Upper Austria. Certain hornstone beds of Middle Jurassic 

 age, found at Piszke, Hungary, the Upper Jurassic pudding-stones of 



Fifi. 45. 



Tertiary Nasselarians from Barbados : .-I, Antlwcyrtis mespilus Elirbg. B, 

 Lychnocaniu7)i hiceriia Ehrbg. C, Diclyomitramovfgdljieri Elirbg. D, Eucyr- 

 tidium degans Ehrbg. E, Ptcrocodon campana Ehrbg. 



