clxvi THE VOYAGE OF H.M.S. CHALLENGER. 



In 1882 Biitsclili still further increased the number of known Eadiolaria from Barbados both 

 by figures and descriptions (L. N. 40), and gave in particular a very accurate morphological analysis 

 of 12 new Nassellaeia (3 S t e p h o i d e a, 3 S p y r o i d e a, and 6 C y r t o i d e a ; L. N. 40 

 Taf. xxxii., xxxiii.). The number of the fossil species collected in the Barbados marl is, however, 

 greater than would appear from the above-quoted communications. My respected friend, Dr. E. 

 Teuscher, of Jena, has, at my request, made a large number (about a thousand) of very accurate 

 drawings with the camera lucida of Polycystina from Barbados (see p. 1760). From these it appears 

 that the variations in the structure of the shells, with respect to number, size, and form of the 

 lattice-pores, of the spines, &c., is much greater than would be supposed from the figures of Ehrenberg 

 and Bury. I have thus come to the conviction that the number of species from Barbados (using 

 the word " species " in the sense understood by those authors) is not less than 400 and probably 

 more than 500. Descriptions of some particularly interesting new species from this series have 

 been included in the systematic account of the Challenger Eadiolaria. A complete critical investi- 

 gation of the Eadiolaria of Barbados, and especially an accurate comparison of these Gainozoic 

 species with the Mesozoic forms from the Jura, on the one hand, and with recent types on the 

 other, must be left to the future for its accomplishment (see § 246). 



B. The Cainozoic Polycystine tripoli or marl of the Mediterranean coast, which is probably 

 always of Miocene origin, forms very extensive mountain ranges both in the south of Europe 

 (Sicily, Calabria, Greece) and in the north of Africa (from Oran to Tripoli) (§ 246). Hitherto, 

 however, only one locality has been thoroTighly investigated, namely, Grotte in the province of 

 Girgenti in Sicily (L. N. 35). In the accurate account which was given of it by Stohr in 1880, 

 118 species were described, distributed in 40 genera (L. N. 35; pp. 72-84); of these 118 species 

 78 are quite new, 25 are identical with previously known fossils, and 29 identical with living forms. 

 Among them are 73 Spumellaria (28 Sphsroidea, 8 Prunoidea, and 37 D i s c o i d e a), 

 but only 40 Nassellakia (1 Stephoidea, 6 S p y r o i d e a, and 33 Cyrtoidea), and 5 

 Ph.eodaeia (Dictyochida). The other parts of Sicily from which the same upper Miocene tripoli 

 has been investigated (belonging to the Tortona stage) have proved less rich than Grotte. The 

 best known of these places is Caltanisetta, since upon three genera discovered here {Haliomma, 

 Cornutclla, Litliocampc) the group Polycystina was founded by Ehrenberg in 1838 (see L. N. 16, p. 3). 

 Afterwards 31 species were described from this locality, of which 23 were again found in Grotte. 

 The richest deposit on the Mediterranean coast, however, appears to be at Oran. A small specimen 

 of the Kieselguhr found there, which was recently sent to me by Professor Steinman, proved to 

 be pure Eadiolarian ooze, very similar to that now found in the Central Pacific, and contained many 

 hitherto undescribed species ; it is deserving of careful investigation and comparison. 



C. Eegarding the Tertiary Eadiolarian clay of the Nicobar Islands, see § 247 and L. N". 25, pp. 

 116-120. Its fauna is incompletely known; probably it is of Miocene or Oligocene origin. 



D. Cainozoic tripoli, containing larger or smaller quantities of Eadiolaria, appears to be rather 

 widely distributed in America. Ehrenberg has described such from South America (polishing-slate 

 from Morro di Mijellones, on the coast between Chili and Bolivia), and from North America (Eich- 

 mond and Petersburg in Virginia, Piscataway in Maryland). Similar deposits are also found in 

 the Bermuda Islands (L. N. 4, 1855-56 ; L. K 6, Taf. 18 ; L. X. 16, pp. 3-9 ; L. N. 41, pp. 475- 

 478, and L. K 25, pp. 2-6). 



