Clxviii THE VOYAGE OF H.M.S. CHALLENGES. 



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 188.0 by 

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

 Pantanelli believes, however, that this jasper is for the most part of Eocene origin ; but from his 

 description, and especially from the morphological character of the forms which 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. N. 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 SPUMELLARIA (6 Sphseroidea and 9 Discoidea) and 

 17 NASSELLAEIA (4 Stephoidea and 13 Cyrtoidea); 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. Ernil von Dunikowski in 1882 described 18 species of fossil Eadiolaria 

 (L. N. 44, pp. 22-34, Taf. iv.-vi) ; most of these are Sphseroidea 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 small 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 well-preserved species from the upper 

 chalk of North Germany (L. N. 29, pp. 76-96, Taf. ii.) ; among them were 1 Sphaeroidea, 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. Palaeozoic Radiolaria. The number of Radiolaria which are known from the 

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

 periods. Here, however, the investigations of recent times have yielded important in- 

 formation ; a few species, at all events, of Polycystina (mostly Sphseroidea) are now 

 known from various Palaeozoic 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 SPUMELLARIA (latticed spheres, ellipsoids, lenses, &c.), but partly also simple 

 NASSELLARIA. 



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

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

 with 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 

 Paleozoic 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. All these very ancient SPUMELLARIA (S p h ce r o i d e a) and NASSELLARIA (Cyrtoidea) 



