clxviii THE VOYAGE OF H.M.S. CHALLENGEE. 



B. Jurassic Eadiolaria from Italy, also found in jasper, which are closely related to the forms 

 from Germany and Switzerland described by Dr. Eiist, were made known so long ago as 1880 by 

 Dante Pantanelli in his treatise I Diaspri della Toscana e i loro Fossili (Eome, 1880, 33 pp. 60 figs.). 

 PantaneUi believes, however, that this jasper is for the most part of Eocene origin ; but fi'om his 

 description, and especially from the morphological character of the forms wliich he figures, it ap- 

 pears very probable " that these Tuscan jaspers from Galestro, like those of the Swiss conglomerates, 

 are found in a secondary locality and belong to the Jurassic period " (Eiist, L. K 51, p. 3). Un- 

 fortunately the figures of Pantanelli are so small and incomplete that a reliable determination of the 

 species is hardly possible ; for example, the lattice-work is only given in ten of the sixty figures. 

 Among the 32 recorded species 15 are Spumellakia (6 Sphseroidea and 9 Discoidea) and 

 17 ISTassellaeia (4 S t e p h o i d e a and 13 C y r t o i d e a) ; many of which seem to be identical 

 with the forms more accurately described by Dr. Eiist (compare p. 1762). 



C. From the Lias of the Alps and more particularly " from the lower Liassic beds of the Schaf- 

 berg near Salzburg," Dr. Emil von Dunikowski in 1882 described 18 species of fossil Eadiolaria 

 (L. N. 44, pp. 22-34, Taf. iv.-vi.) ; most of these are Sphteroidea and Discoidea and ap- 

 pear to have been more or less altered by petrological changes ; their spongy structure is probably 

 secondary. 



D. Cretaceous Eadiolaria have been hitherto described only in very smaU numbers ; quite 

 recently Dr. Eiist has found a larger number chiefly in flints from the English chalk, but they have 

 not yet been published. In 1876 Zittel described 6 very weU-preserved species from the upper 

 chalk of North Germany (L. N. 29, pp. 76-96, Taf. ii.) ; among them were 1 Sphsroidea, 1 

 Discoidea, 1 Dictyocha, and 3 Cyrtoidea. 



E. Triassic Eadiolaria have recently been discovered by Dr. Eiist in chert, but have not yet 

 been described. 



244. Palceozoic Radiolaria. — The number of Eadiolaria which are known from the 

 Palseozoic or Primary formations is much less than from either the Mesozoic or Cainozoic 

 periods. Here, however, the inA^estigations of recent times have j^elded important in- 

 formation ; a few species, at all events, of Polycystina (mostly S p h se r o i d e a) are now 

 kno-wTi from various Palseozoic formations, and not only from the Permian (" Zechstein ") 

 and the Coal-measures, but also from the older Devonian and Silurian systems. Even in 

 the still older Cambrian rocks a few fossil Radiolaria have been found. All these Palaeo- 

 zoic Radiolaria are Polycystina of very simple form and primitive structure, mostly 

 simple Spumellaeia (latticed spheres, ellipsoids, lenses, &c.), but partly also simple 

 Nassellaria. 



The important discoveries ^hich have recently been made by Dr. Eiist regarding the occurrence 

 of Eadiolaria in all the Palfeozoic formations have not yet been published. From conversations 

 \vith this estimable palaeontologist I have learned, however, that he has pursued his fruitful investi- 

 gation of the Mesozoic quartzites (§ 243), and has met with no less success in the case of similar 

 PaL-eozoic structures. Although the number of species hitherto discovered is relatively small, the 

 important conclusion appears to be warranted that they extend as far as the Silurian and Cambrian 

 systems. AH these very ancient Spumellaeia (Sphaeroidea) and Nassellaela. (Cyrtoidea) 



