Chapter IX: Geographical Distribution (2)

+----------+-----------+--------+------------+-----------+--------------+
| | | | Bottom | | Relative |
|Challenger| Locality. |Depth in|Temperature,| Nature of | Abundance of |
| Station. | |Fathoms.| ° F. | Bottom. | Radiolaria. |
+----------+-----------+--------+------------+-----------+--------------+
| | | | | | |
| 1. | N. Atl. | 1890 | 36.8 | gl. oz. | D few |
| 2. | " | 1945 | 36.8 | gl. oz. | E very few |
| 5. | " | 2740 | 37.0 | r. cl. | D few |
| 9. | " | 3150 | 36.8 | r. cl. | E very few |
| 24. | Tr. Atl. | 390 | ... | pt. oz. | D few |
| | | | | | |
| 32. | N. Atl. | 2250 | 36.7 | gl. oz. | E very few |
| 45. | " | 1240 | 37.2 | bl. m. | E " |
| 50. | " | 1250 | 38.0 | bl. m. | E " |
| 64. | " | 2700 | ... | r. cl. | D few |
| 76. | " | 900 | 40.0 | pt. oz. | D " |
| | | | | | |
| 98. | Tr. Atl. | 1750 | 36.7 | gl. oz. | C many |
| 106. | " | 1850 | 36.6 | gl. oz. | C " |
| 108. | " | 1900 | 36.8 | gl. oz. | C " |
| 111. | " | 2475 | 33.7 | gl. oz. | C " |
| 120. | " | 675 | ... | r. m. | D few |
| | | | | | |
| 132. | S. Atl. | 2050 | 35.0 | gl. oz. | C many |
| 134. | " | 2025 | 36.0 | gl. oz. | C " |
| 137. | " | 2550 | 34.5 | r. cl. | D few |
| 138. | " | 2650 | 35.1 | r. cl. | D " |
| 143. | S. Ind. | 1900 | 35.6 | gl. oz. | E very few |
| | | | | | |
| 144. | " | 1570 | 35.8 | gl. oz. | E " |
| 145. | " | 140 | ... | volc. s. | D few |
| 146. | " | 1375 | 35.6 | gl. oz. | C many |
| 147. | " | 1600 | 34.2 | di. oz. | C " |
| 148. | " | 210 | ... {| gravel, } | D few |
| | | | {| shells } | |
| | | | | | |
| 149H. | " | 127 | ... | volc. m. | D " |
| 150. | " | 150 | 35.2 | gravel | D " |
| 151. | " | 75 | ... | volc. m. | D " |
| 152. | " | 1260 | ... | di. oz. | C many |
| 153. | " | 1675 | ... | bl. m. | C " |
| | | | | | |
| 154. | " | 1800 | ... | bl. m. | C " |
| 155. | " | 1300 | ... | bl. m. | C " |
| 156. | " | 1975 | ... | di. oz. | B numerous |
| 157. | " | 1950 | 32.1 | di. oz. | B " |
| 158. | " | 1800 | 33.5 | gl. oz. | B " |
| | | | | | |
| 159. | " | 2150 | 34.5 | gl. oz. | B " |
| 160. | " | 2600 | 33.9 | r. cl. | C many |
| 162. | " | 38 | ... | sand | E very few |
| 163. | S. Pac. | 2200 | 34.5 | gr. m. | E " |
| 164A. | " | 1200 | ... | gr. m. | E " |
| | | | | | |
| 165. | S. Pac. | 2600 | 34.5 | r. cl. | D few |
| 166. | " | 275 | 50.8 | gl. oz. | D " |
| 169. | " | 700 | 40.0 | bl. m. | D " |
| 175. | Tr. Pac. | 1350 | 36.0 | gl. oz. | E very few |
| 181. | " | 2440 | 35.8 | r. cl. | E " |
| | | | | | |
| 193. | " | 2800 | 38.0 | bl. m. | D few |
| 195. | " | 1425 | 38.0 | bl. m. | C many |
| 197. | " | 1200 | 35.9 | bl. m. | D few |
| 198. | " | 2150 | 38.9 | bl. m. | C many |
| 200. | " | 250 | ... | gr. m. | B numerous |
| | | | | | |
| 201. | " | 82 | ... | st. & gra.| C many |
| 202. | " | 2550 | 50.5 | bl. m. | B numerous |
| 205. | " | 1050 | 37.0 | bl. m. | C many |
| 206. | " | 2100 | 36.5 | bl. m. | B numerous |
| 211. | " | 2225 | 50.5 | bl. m. | B " |
| | | | | | |
| 213. | " | 2050 | 38.8 | bl. m. | C many |
| 214. | " | 500 | 41.8 | bl. m. | C " |
| 215. | " | 2550 | 35.4 | r. cl. | C many |
| 216A | " | 2000 | 35.4 | gl. oz. | B numerous |
| 217. | " | 2000 | 35.2 | bl. m. | C many |
| | | | | | |
| 218. | " | 1070 | 36.4 | bl. m. | C " |
| 220. | " | 1100 | 36.2 | gl. oz. | C " |
| 221. | " | 2650 | 35.4 | r. cl. | B numerous |
| 222. | " | 2450 | 35.2 | r. cl. | B " |
| 223. | " | 2325 | 35.5 | gl. oz. | B " |
| | | | | | |
| 224. | " | 1850 | 35.4 | gl. oz. | B " |
| 225. | " | 4475 | 35.2 | rad. oz. | A very many |
| 226. | " | 2300 | 35.5 | rad. oz. | A " |
| 230. | N. Pac. | 2425 | 35.5 | r. cl. | C many |
| 231. | " | 2250 | 35.2 | bl. m. | C " |
| | | | | | |
| 232. | " | 345 | 41.1 | gr. m. | C " |
| 234. | " | 2675 | 35.8 | bl. m. | B numerous |
| 235. | " | 565 | 38.1 | gr. m. | D few |
| 236. | " | 775 | 37.6 | gr. m. | C many |
| 237. | " | 1875 | 35.3 | bl. m. | C " |
| | | | | | |
| 238. | " | 3950 | 35.0 | r. cl. | B numerous |
| 239. | " | 3625 | 35.1 | r. cl. | B " |
| 240. | " | 2900 | 34.9 | r. cl. | B " |
| 241. | " | 2300 | 35.1 | r. cl. | A very many |
| 242. | " | 2575 | 35.1 | r. cl. | AII " |
| | | | | | |
| 243. | " | 2800 | 35.0 | r. cl. | AII " |
| 244. | " | 2900 | 35.3 | r. cl. | AII " |
| 245. | " | 2775 | 34.9 | r. cl. | AII " |
| 246. | " | 2050 | 35.1 | gl. oz. | B numerous |
| 247. | " | 2530 | 35.2 | r. cl. | C many |
| | | | | | |
| 248. | " | 2900 | 35.1 | r. cl. | C " |
| 249. | " | 3000 | 35.2 | r. cl. | B numerous |
| 250. | " | 3050 | 35.0 | r. cl. | B " |
| 251. | " | 2950 | 35.1 | r. cl. | B " |
| 252. | " | 2740 | 35.3 | r. cl. | B " |
| | | | | | |
| 253. | " | 3125 | 35.1 | r. cl. | B " |
| 254. | " | 3025 | 35.0 | r. cl. | C many |
| 255. | " | 2850 | 35.0 | r. cl. | C " |
| 256. | " | 2950 | 35.2 | r. cl. | B numerous |
| 257. | " | 2875 | 34.9 | r. cl. | C many |
| | | | | | |
| 258. | " | 2775 | 35.2 | r. cl. | C " |
| 259. | Tr. Pac. | 2225 | 34.9 | r. cl. | C " |
| 261. | " | 2050 | 35.2 | volc. m. | C many |
| 262. | " | 2875 | 35.2 | r. cl. | C " |
| 263. | " | 2650 | 35.1 | r. cl. | B numerous |
| | | | | | |
| 264. | " | 3000 | 35.2 | r. cl. | C many |
| 265. | " | 2900 | 35.0 | r. cl. | A very many |
| 266. | " | 2750 | 35.1 | rad. oz. | A " |
| 267. | " | 2700 | 35.0 | rad. oz. | A " |
| 268. | " | 2900 | 34.8 | rad. oz. | A " |
| | | | | | |
| 269. | " | 2550 | 35.2 | rad. oz. | A " |
| 270. | " | 2925 | 34.6 | gl. oz. | A " |
| 271. | " | 2425 | 35.0 | gl. oz. | A " |
| 272. | " | 2600 | 35.1 | rad. oz. | A " |
| 273. | " | 2350 | 34.5 | rad. oz. | A " |
| | | | | | |
| 274. | " | 2750 | 35.1 | rad. oz. | A " |
| 275. | " | 2610 | 35.0 | r. cl. | B numerous |
| 276. | " | 2350 | 35.1 | r. cl. | C many |
| 280. | " | 1940 | 35.3 | gl. oz. | D few |
| 281. | " | 2385 | 34.9 | r. cl. | C many |
| | | | | | |
| 282. | S. Pac. | 2450 | 35.1 | r. cl. | C " |
| 283. | " | 2075 | 35.4 | gl. oz. | D few |
| 284. | " | 1985 | 35.1 | gl. oz. | C many |
| 285. | " | 2375 | 35.0 | r. cl. | D few |
| 286. | " | 2335 | 34.8 | r. cl. | D " |
| | | | | | |
| 287. | " | 2400 | 34.7 | r. cl. | D " |
| 288. | " | 2600 | 34.8 | r. cl. | B numerous |
| 289. | " | 2550 | 34.8 | r. cl. | B " |
| 290. | " | 2300 | 34.9 | r. cl. | C many |
| 291. | " | 2250 | 34.6 | r. cl. | C " |
| | | | | | |
| 292. | " | 1600 | 35.2 | gl. oz. | C " |
| 293. | " | 2025 | 34.4 | gl. oz. | C " |
| 294. | " | 2270 | 34.6 | r. cl. | D few |
| 295. | " | 1500 | 35.3 | gl. oz. | C many |
| 296. | " | 1825 | 35.3 | gl. oz. | D few |
| | | | | | |
| 297. | " | 1775 | 35.5 | gl. oz. | D " |
| 298. | " | 2225 | 35.6 | bl. m. | C many |
| 299. | " | 2160 | 35.2 | bl. m. | C " |
| 300. | " | 1375 | 35.5 | gl. oz. | B numerous |
| 302. | " | 1450 | 35.6 | gl. oz. | B " |
| | | | | | |
| 303. | " | 1325 | 36.0 | bl. m. | D few |
| 304. | " | 45 | ... | gr. m. | E very few |
| 318. | S. Atl. | 2040 | 33.7 | bl. m. | C few |
| 319. | " | 2425 | 32.7 | bl. m. | C " |
| 323. | " | 1900 | 33.1 | bl. m. | C " |
| | | | | | |
| 324. | " | 2800 | 32.6 | bl. m. | B numerous |
| 325. | " | 2650 | 32.7 | bl. m. | B " |
| 326. | " | 2775 | 32.7 | bl. m. | C many |
| 327. | " | 2900 | 32.8 | bl. m. | C " |
| 328. | " | 2900 | 32.9 | bl. m. | B numerous |
| | | | | | |
| 329. | " | 2675 | 32.3 | r. cl. | C many |
| 330. | " | 2440 | 32.7 | r. cl. | C " |
| 331. | " | 1715 | 35.4 | gl. oz. | B numerous |
| 332. | " | 2200 | 34.0 | gl. oz. | B " |
| 333. | " | 2025 | 35.3 | gl. oz. | B " |
| | | | | | |
| 334. | " | 1915 | 35.8 | gl. oz. | C many |
| 335. | " | 1425 | 37.0 | pt. oz. | D few |
| 338. | Tr. Atl. | 1990 | 36.3 | gl. oz. | D few |
| 340. | " | 1500 | 37.6 | pt. oz. | E very few |
| 341. | " | 1475 | 38.2 | pt. oz. | E " |
| | | | | | |
| 342. | " | 1445 | 37.5 | pt. oz. | D few |
| 343. | " | 425 | 40.3 | volc. s. | E very few |
| 344. | " | 420 | ... | volc. s. | E " |
| 345. | " | 2010 | 36.8 | gl. oz. | D few |
| 346. | " | 2350 | 34.0 | gl. oz. | C many |
| | | | | | |
| 347. | " | 2250 | 36.2 | gl. oz. | B numerous |
| 348. | " | (2450) | ... | (Pelag.) | B " |
| 349. | " | ... | ... | (Pelag.) | B " |
| 350. | " | ... | ... | (Pelag.) | B " |
| 351. | " | ... | ... | (Pelag.) | B " |
| | | | | | |
| 352. | " | ... | ... | (Pelag.) | B " |
| 353. | N. Atl. | 2965 | 37.6 | r. cl. | C many |
| 354. | " | 1675 | 37.8 | gl. oz. | D few |
+----------+-----------+--------+------------+-----------+--------------+

+----------+--------+-----------------------+---------------------------+
| | | | |
|Challenger| Date. |Latitude and Longitude.| Nearest Land. |
| Station. | | | |
+----------+--------+-----------------------+---------------------------+
| | 1873. | | |
| 1. |Feb. 15|27° 24' N., 16° 55' W.|S. of Tenerife. |
| 2. | " 17|25° 52' N., 19° 22' W.|S.W. of the Canary Islands.|
| 5. | " 21|24° 20' N., 24° 28' W.|S.W. of the Canary Islands.|
| 9. | " 26|23° 23' N., 35° 11' W.| (Ocean). |
| 24. |Mar. 25|18° 38' N., 65° 5' W.|Culebra (Antilles). |
| | | | |
| 32. |April 3|31° 49' N., 64° 55' W.|Bermuda. |
| 45. |May 3|38° 34' N., 72° 10' W.|S. of New York. |
| 50. | " 21|42° 8' N., 63° 39' W.|S. of Halifax. |
| 64. |June 20|35° 35' N., 50° 27' W.| (Ocean). |
| 76. |July 3|38° 11' N., 27° 9' W.|Azores. |
| | | | |
| 98. |Aug. 14| 9° 21' N., 18° 28' W.|W. of Sierra Leone. |
| 106. | " 25| 1° 47' N., 24° 26' W.| (Ocean). |
| 108. | " 27| 1° 10' N., 28° 23' W.| (Ocean). |
| 111. | " 31| 1° 45' S., 30° 58' W.| (Ocean). |
| 120. |Sept. 9| 8° 37' S., 34° 28' W.|Pernambuco. |
| | | | |
| 132. |Oct. 10|35° 25' S., 23° 40' W.|Tristan da Cunha. |
| 134. | " 14|36° 12' S., 12° 16' W.|Tristan da Cunha. |
| 137. | " 23|35° 59' S., 1° 34' E.| (Ocean). |
| 138. | " 25|36° 22' S., 8° 12' E.| (Ocean). |
| 143. |Dec. 19|36° 48' S., 19° 24' E.|Cape of Good Hope. |
| | | | |
| 144. | " 24|45° 57' S., 34° 39' E.| (Ocean). |
| 145. | " 27|46° 43' S., 38° 4' E.|Prince Edward Island. |
| 146. | " 29|46° 46' S., 45° 31' E.| (Ocean). |
| 147. | " 30|46° 16' S., 48° 27' E.|W. of the Crozet Islands. |
| | 1874. | | |
| 148. |Jan. 3|46° 47' S., 51° 37' E.|E. of the Crozet Islands. |
| | | | |
| 149H. | " 29|48° 45' S., 69° 14' E.|Kerguelen Island. |
| 150. |Feb. 2|52° 4' S., 71° 22' E.|N. of Heard Island. |
| 151. | " 7|52° 59' S., 73° 33' E.|Heard Island. |
| 152. | " 11|60° 52' S., 80° 20' E.|(Ocean). |
| 153. | " 14|65° 42' S., 79° 49' E.|Antarctic Ice. |
| | | | |
| 154. | " 19|64° 37' S., 85° 49' E.|Antarctic Ice. |
| 155. | " 23|64° 18' S., 94° 47' E.|Antarctic Ice. |
| 156. | " 26|62° 26' S., 95° 44' E.| (Ocean). |
| 157. |Mar. 3|53° 55' S., 108° 35' E.| (Ocean). |
| 158. | " 7|50° 1' S., 123° 4' E.| (Ocean). |
| | | | |
| 159. | " 10|47° 25' S., 130° 22' E.| (Ocean). |
| 160. | " 13|42° 42' S., 134° 10' E.| (Ocean). |
| 162. |April 2|39° 10' S., 146° 37' E.|Bass Strait. |
| 163. | " 4|36° 57' S., 150° 34' E.|Port Jackson. |
| 164A. |June 13|34° 9' S., 151° 55' E.|W. of Sydney. |
| | | | |
| 165. | " 17|34° 50' S., 155° 28' E.| (Ocean). |
| 166. | " 23|38° 50' S., 169° 20' E.|W. of New Zealand. |
| 169. |July 10|37° 34' S., 179° 22' E.|E. of New Zealand. |
| 175. |Aug. 12|19° 2' S., 177° 10' E.|Fiji Islands. |
| 181. | " 25|13° 50' S., 151° 49' E.|Louisiades. |
| | | | |
| 193. |Sept. 28| 5° 24' S., 130° 37' E.|Banda Sea. |
| 195. |Oct. 3| 4° 21' S., 129° 7' E.|Banda Sea. |
| 197. | " 14| 0° 41' N., 126° 37' E.|E. of Celebes. |
| 198. | " 20| 2° 55' N., 124° 58' E.|N. of Celebes. |
| 200. | " 23| 6° 47' N., 122° 28' E.|W. of Mindanao. |
| | | | |
| 201. | " 26| 7° 3' N., 121° 48' E.|W. of Mindanao. |
| 202. | " 27| 8° 32' N., 121° 55' E.|W. of Mindanao. |
| 205. |Nov. 13|16° 42' N., 119° 22' E.|W. of Luzon. |
| | 1875. | | |
| 206. |Jan. 8|17° 54' N., 117° 14' E.|W. of Luzon. |
| 211. | " 28| 8° 0' N., 121° 42' E.|W. of Mindanao. |
| | | | |
| 213. |Feb. 8| 5° 47' N., 124° 1' E.|S. of Mindanao. |
| 214. | " 10| 4° 33' N., 127° 6' E.|N. of Gilolo. |
| 215. | " 12| 4° 19' N., 130° 15' E.|N. of Gilolo. |
| 216A. | " 16| 2° 56' N., 134° 11' E.|S. of Pelew Islands. |
| 217. | " 22| 0° 39' S., 138° 55' E.|N. of New Guinea. |
| | | | |
| 218. |Mar. 1| 2° 33' S., 144° 4' E.|N. of New Guinea. |
| 220. | " 11| 0° 42' S., 147° 0' E.|N. of New Guinea. |
| 221. | " 13| 0° 40' N., 148° 41' E.| (Ocean). |
| 222. | " 16| 2° 15' N., 146° 16' E.| (Ocean). |
| 223. | " 19| 5° 31' N., 145° 13' E.|Carolines. |
| | | | |
| 224. | " 21| 7° 45' N., 144° 20' E.|Carolines. |
| 225. | " 23|11° 24' N., 143° 16' E.|Ocean } |
| 226. | " 25|14° 44' N., 142° 13' E.|Ocean } North-West Pacific,|
| 230. |April 5|26° 29' N., 137° 57' E.|Ocean } between Carolines |
| 231. | " 9|31° 8' N., 137° 8' E.|Ocean } and Japan. |
| | | | } |
| 232. |May 12|35° 11' N., 139° 28' E.|Ocean } |
| 234. |June 3|32° 31' N., 135° 39' E.|S. of Japan. |
| 235. | " 4|34° 7' N., 138° 0' E.|S. of Japan. |
| 236. | " 5|34° 58' N., 139° 29' E.|S. of Japan. |
| 237. | " 17|34° 37' N., 140° 32' E.|S. of Japan. |
| | | | |
| 238. | " 18|35° 18' N., 144° 8' E.|Ocean } |
| 239. | " 19|35° 18' N., 147° 9' E.|Ocean } |
| 240. | " 21|35° 20' N., 153° 39' E.|Ocean } |
| 241. | " 23|35° 41' N., 157° 42' E.|Ocean } |
| 242. | " 24|35° 29' N., 161° 52' E.|Ocean } |
| | | | } |
| 243. | " 26|35° 24' N., 166° 35' E.|Ocean } North Pacific, |
| 244. | " 28|35° 22' N., 169° 53' E.|Ocean } between Japan and |
| 245. | " 30|36° 23' N., 174° 31' E.|Ocean } San Francisco |
| 246. |July 2|36° 10' N., 178° 0' E.|Ocean } (35°-38° N. lat., |
| 247. | " 3|35° 49' N., 179° 57' W.|Ocean } 144°-156° W. long.)|
| | | | } |
| 248. | " 5|37° 41' N., 177° 4' W.|Ocean } |
| 249. | " 7|37° 59' N., 171° 48' W.|Ocean } |
| 250. | " 9|37° 49' N., 166° 47' W.|Ocean } |
| 251. | " 10|37° 37' N., 163° 26' W.|Ocean } |
| 252. | " 12|37° 52' N., 160° 17' W.|Ocean } |
| | | | } |
| 253. | " 14|38° 9' N., 156° 25' W.|Ocean |
| 254. | " 17|35° 13' N., 154° 43' W.|Ocean } |
| 255. | " 19|32° 28' N., 154° 33' W.|Ocean } North Pacific |
| 256. | " 21|30° 22' N., 154° 56' W.|Ocean } (35°-23° N. lat., |
| 257. | " 23|27° 33' N., 154° 55' W.|Ocean }154°-156° W. long.).|
| | | | } |
| 258. | " 24|26° 11' N., 155° 12' W.|Ocean } |
| 259. | " 26|23° 3' N., 156° 6' W.|Ocean } |
| 261. |Aug. 12|20° 18' N., 157° 14' W.|Sandwich Islands. |
| 262. | " 20|19° 12' N., 154° 14' W.|Sandwich Islands. |
| 263. | " 21|17° 33' N., 153° 36' W.|Ocean } |
| | | | } |
| 264. | " 23|14° 19' N., 152° 37' W.|Ocean } |
| 265. | " 25|12° 42' N., 152° 1' W.|Ocean } |
| 266. | " 26|11° 7' N., 152° 3' W.|Ocean } Tropical Central |
| 267. | " 28| 9° 28' N., 150° 49' W.|Ocean } Pacific, between |
| 268. | " 30| 7° 35' N., 149° 49' W.|Ocean } Sandwich and |
| | | | } |
| 269. |Sept. 2| 5° 54' N., 147° 2' W.|Ocean } Paumotu |
| 270. | " 4| 2° 34' N., 149° 9' W.|Ocean } (17° N. lat. to |
| 271. | " 6| 0° 33' S., 151° 34' W.|Ocean } 11° S. lat.). |
| 272. | " 8| 3° 48' S., 152° 56' W.|Ocean } |
| 273. | " 9| 5° 11' S., 152° 56' W.|Ocean } |
| | | | } |
| 274. | " 11| 7° 25' S., 152° 15' W.|Ocean } |
| 275. | " 14|11° 20' S., 150° 30' W.|Ocean } |
| 276. | " 16|13° 28' S., 149° 30' W.|Paumotu. |
| 280. |Oct. 4|18° 40' S., 149° 52' W.|S. of Tahiti. |
| 281. | " 6|22° 21' S., 150° 17' W.|Tubuai Islands. |
| | | | |
| 282. | " 7|23° 46' S., 149° 59' W.|Tubuai Islands. |
| 283. | " 9|26° 9' S., 145° 17' W.|N. of Oparo Island. |
| 284. | " 11|28° 22' S., 141° 22' W.|S. of Oparo Island. |
| 285. | " 14|32° 36' S., 137° 43' W.|Ocean } |
| 286. | " 16|33° 29' S., 133° 22' W.|Ocean } |
| | | | |
| 287. | " 10|36° 32' S., 132° 52' W.|Ocean } |
| 288. | " 21|40° 3' S., 132° 58' W.|Ocean } |
| 289. | " 23|39° 41' S., 131° 23' W.|Ocean } |
| 290. | " 25|39° 16' S., 124° 7' W.|Ocean } Open South Pacific |
| 291. | " 27|39° 13' S., 118° 49' W.|Ocean } Ocean, between New |
| | | | } Zealand and |
| 292. | " 29|38° 43' S., 112° 31' W.|Ocean } Valparaiso. |
| 293. |Nov. 1|39° 4' S., 105° 5' W.|Ocean } |
| 294. | " 3|39° 22' S., 98° 46' W.|Ocean } |
| 295. | " 5|38° 7' S., 94° 4' W.|Ocean } |
| 296. | " 9|38° 6' S., 88° 2' W.|Ocean } |
| | | | } |
| 297. | " 11|37° 29' S., 83° 7' W.|Ocean } |
| 298. | " 17|34° 7' S., 73° 56' W.|W. of Valparaiso. |
| 299. |Dec. 14|33° 31' S., 74° 43' W.|W. of Valparaiso. |
| 300. | " 17|33° 42' S., 78° 18' W.|N. of Juan Fernandez. |
| 302. | " 28|42° 43' S., 82° 11' W.| (Ocean). |
| | | | |
| 303. | " 30|45° 31' S., 78° 9' W.|W. of Patagonia. |
| 304. | " 31|46° 53' S., 75° 12' W.|W. of Patagonia. |
| | 1876. | | |
| 318. |Feb. 11|42° 32' S., 56° 29' W.| (Ocean). |
| 319. | " 12|41° 54' S., 54° 48' W.| (Ocean). |
| 323. | " 28|35° 39' S., 50° 47' W.|W. of Buenos Ayres. |
| | | | } |
| 324. | " 29|36° 9' S., 48° 22' W.|Ocean } |
| 325. |Mar. 2|36° 44' S., 46° 16' W.|Ocean } |
| 326. | " 3|37° 3' S., 44° 17' W.|Ocean } Open South Atlantic|
| 327. | " 4|36° 48' S., 42° 45' W.|Ocean } Ocean, between |
| 328. | " 6|37° 38' S., 39° 36' W.|Ocean } Buenos Ayres and |
| | | | } |
| 329. | " 7|37° 31' S., 36° 7' W.|Ocean } Tristan da Cunha |
| 330. | " 8|37° 45' S., 33° 0' W.|Ocean } (35°-37° S. lat., |
| 331. | " 9|37° 47' S., 30° 20' W.|Ocean } 21°-48° W. long.). |
| 332. | " 10|37° 29' S., 27° 31' W.|Ocean } |
| 333. | " 13|35° 36' S., 21° 12' W.|Ocean } |
| | | | |
| 334. | " 14|35° 45' S., 18° 31' W.|W. of Tristan da Cunha. |
| 335. | " 16|32° 24' S., 13° 5' W.|N. of Tristan da Cunha. |
| 338. | " 21|21° 15' S., 14° 2' W.|(Ocean). |
| 340. | " 24|14° 33' S., 13° 42' W.|Ocean } |
| 341. | " 25|12° 16' S., 13° 44' W.|Ocean } W. of St. Helena. |
| | | | |
| 342. | " 26| 9° 43' S., 13° 51' W.|Ocean } |
| 343. | " 27| 8° 3' S., 14° 27' W.|Ascension Island. |
| 344. |April 3| 7° 54' S., 14° 28' W.|Ascension Island. |
| 345. | " 4| 5° 45' S., 14° 25' W.|Ocean } |
| 346. | " 6| 2° 42' S., 14° 41' W.|Ocean } Tropical Atlantic, |
| | | | } between Ascension |
| 347. | " 7| 0° 15' S., 14° 25' W.|Ocean } and Sierra Leone. |
| 348. | " 9| 3° 10' N., 14° 51' W.|Ocean } |
| 349. | " 10| 5° 28' N., 14° 38' W.|Ocean } |
| 350. | " 11| 7° 33' N., 15° 16' W.|W. of Sierra Leone. |
| 351. | " 12| 9° 9' N., 16° 41' W.|W. of Sierra Leone. |
| | | | |
| 352. | " 13|10° 55' N., 17° 46' W.|W. of Sierra Leone. |
| 353. |May 3|26° 21' N., 33° 37' W.|W. of Canary Islands. |
| 354. | " 6|32° 41' N., 36° 6' W.|S. of Azores. |
+----------+--------+-----------------------+---------------------------+

{clxiv}CHAPTER X.--GEOGRAPHICAL DISTRIBUTION.

(§§ 241-250.)

241. _Historical Distribution._--Radiolaria are found fossil in all the more important groups of the sedimentary rocks of the earth's crust. Whilst a few years ago their well-preserved siliceous skeletons were only known in considerable quantity from Cainozoic marls (§ 242), very many SPUMELLARIA and NASSELLARIA have recently been found in Mesozoic and a few in Palæozoic strata. By the aid of improved modern methods of investigation (especially by the preparation of thin sections of very hard rocks) it has been shown that many hard siliceous minerals, especially cryptocrystalline quartz, contain numerous well-preserved Radiolaria, and sometimes are mainly composed of closely compacted masses of such siliceous shells; of this kind are many quartzites of the Jura (§ 243). These Jurassic quartzes (Switzerland), as well as the Tertiary marls (Barbados) and clays (Nicobar Islands), are to be regarded as "fossil Radiolarian ooze" (§ 237). Dense masses of compressed SPUMELLARIA and NASSELLARIA form the principal part of these rocks. Isolated or in smaller quantities, fossil Polycystina, belonging to different families of SPUMELLARIA and NASSELLARIA, also occur in in other rocks, and even in some of Palæozoic origin. Since specimens have also been recently found both in Silurian and Cambrian strata, it may be stated that as regards their historical distribution, Radiolaria occur in all fossiliferous sedimentary deposits, from the oldest to those of the present time.

242. _Cainozoic Radiolaria._--The great majority of fossil Radiolaria which have hitherto been described, belong to the Cainozoic or Tertiary period, and in fact, to its middle portion, the Miocene period. At this period the richest and most important of all the Radiolarian formations were deposited, such as the pure "Polycystine marl" of Barbados (see note A), also that of Grotte in Sicily (see note B), and the clay of the Nicobar Islands (see note C). Besides the above-mentioned deposits, which may be designated "pure" fossil Radiolarian ooze, many deposits containing these organisms have recently been discovered in widely separated parts of the earth, partly of the nature of tripoli or marl, partly resembling clay. Among these may be mentioned in the first place many coasts and islands of the Mediterranean, both on the south coast of Europe (Sicily, Calabria, Greece), and the north coast of Africa (from Oran to Tripoli). The extensive layers of tripoli which are found in these Mediterranean Tertiary mountains belong to the upper Miocene (Tortona stage), and consist partly of marl rich in calcareous matter, and resembling chalk, partly passing over into plastic clay or "Kieselguhr" (§ 246). The quantity of Radiolaria contained varies, and is more conspicuous the fewer the calcareous shells of Foraminifera present. Similar Tertiary Polycystine formations occur in some parts of America (see note D); probably they have a very wide distribution. In their general morphological characters, the Tertiary SPUMELLARIA and NASSELLARIA {clxv}are related to those forms which are found in the recent Radiolarian ooze of the depths of the Pacific, especially to the species which are characteristic of the Challenger Stations 225, 226, 265 and 268. Many living genera and families (_e.g._, most #Larcoidea# and #Stephoidea#) have not yet been found in the Tertiary formations.

A. The famous Polycystine marl of Barbados in the Antilles, which Robert
Schomburgk discovered forty years ago, belongs to the Miocene formation,
and is the richest and best known of all the important Radiolarian
deposits (see L. N. 16, pp. 5-8). After Ehrenberg had published in
December 1846 the first preliminary communication regarding its
composition out of masses of well-preserved Polycystina, he was able in
the following year to describe no less than 282 species from it; he
distributed these in 44 genera and 7 families (L. N. 4, 1847, p. 54). In
the year 1854 Ehrenberg published figures of 33 species in his
Mikrogeologie (L. N. 6, Taf. xxxvi.); but it was only in 1873 that he
published descriptions of 265 species (Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, Jan. 30, pp. 213-263). Finally there followed in 1875 his
Fortsetzung der Mikrogeologischen Studien, mit specieller Rücksicht auf
den Polycystinen-Mergel von Barbados (L. N. 25). On the thirty plates
which accompany this the last work of Ehrenberg, 282 species are figured
and named, of which 54 are SPUMELLARIA (13 #Sphæroidea#, 8 #Prunoidea#,
33 #Discoidea#), and 228 NASSELLARIA (2 #Stephoidea#, 38 #Spyroidea#, and
188 #Cyrtoidea#). The fourth section of this memoir contains a survey of
the Polycystine formation of Barbados (pp. 106-115), and the fifth
section the special description of a large specimen of rock from Mount
Hillaby in Barbados (see also L. N. 28, p. 117, and L. N. 41, pp.
476-478). The account given by Ehrenberg of the Polycystina of Barbados
is in many respects very incomplete, and very far from exhausting this
rich mine of remarkable forms. This may be readily seen from the
twenty-five plates of figures of Polycystins in the Barbados Chalk
Deposit published by Bury in 1862 (L. N. 17). The number of species here
figured (140 to 142) is about half of those given by Ehrenberg; and there
are among them numerous generic types, some of great interest, which were
entirely overlooked by the latter; _e.g._ _Saturnalis_ (#Sphæroidea#),
_Cannartidium_ (#Prunoidea#), _Tympanidium_ (#Stephoidea#),
_Cinclopyramis_ (#Cyrtoidea#), &c. Finally, Ehrenberg always (until 1875)
ignored Bury's atlas, which had been published thirteen years ago and was
quite accessible to him. How different were the contents of the two works
may easily be seen from the following abstract.

_Comparative View of the Species of Fossil Radiolaria from Barbados made known by the figures of Bury in 1862 and of Ehrenberg in 1875._

+-------------------+--------------------+--------+-----------+-------+
| Legion. | Order. | Bury. | Ehrenberg.| Total.|
+-------------------+--------------------+--------+-----------+-------+
| I. Legion | { 1. Sphæroidea | 16 | 13 | 29 |
| SPUMELLARIA | { 2. Prunoidea | 10 | 8 | 18 |
| (PERIPYLEA). | { 3. Discoidea | 37 | 33 | 70 |
| | | | | |
| II. Legion | { 4. Stephoidea | 5 | 2 | 7 |
| NASSELLARIA | { 5. Spyroidea | 13 | 38 | 51 |
| (MONOPYLEA). | { 6. Cyrtoidea | 60 | 188 | 248 |
+-------------------+--------------------+--------+-----------+-------+
| Total, | 141 | 282 | 423 |
+----------------------------------------+--------+-----------+-------+

{clxvi}In 1882 Bütschli still further increased the number of known
Radiolaria from Barbados both by figures and descriptions (L. N. 40), and
gave in particular a very accurate morphological analysis of 12 new
NASSELLARIA (3 #Stephoidea#, 3 #Spyroidea#, and 6 #Cyrtoidea#; 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. R. 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 Radiolaria. A complete critical investigation of the
Radiolaria of Barbados, and especially an accurate comparison of these
Cainozoic 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 thoroughly investigated, namely, Grotte in the
province of Girgenti in Sicily (L. N. 35). In the accurate account which
was given of it by Stöhr 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 #Sphæroidea#, 8
#Prunoidea#, and 37 #Discoidea#), but only 40 NASSELLARIA (1
#Stephoidea#, 6 #Spyroidea#, and 33 #Cyrtoidea#), and 5 PHÆODARIA
(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_,
_Cornutella_, _Lithocampe_) 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 Radiolarian 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. Regarding the Tertiary Radiolarian 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
Radiolaria, 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 (Richmond and Petersburg in Virginia, Piscataway in Maryland).
Similar deposits are also found in the Bermuda Islands (L. N. 4, 1855-56;
L. N. 6, Taf. 18; L. N. 16, pp. 3-9; L. N. 41, pp. 475-478, and L. N. 25,
pp. 2-6).

{clxvii}243. _Mesozoic Radiolaria._--From the Mesozoic or Secondary period numerous well-preserved Radiolaria have recently been described. They belong for the most part to the Jurassic formation (see notes A, B, C), whilst the more recent Chalk (see note D) and the older Trias (see note E) have hitherto yielded but few species. All the main divisions of the Jura, both the upper (Malm) and the middle (Dogger), and especially the lower (Lias) appear in certain localities to be very rich in well-preserved shells of fossil Polycystina. Most of these are aggregated together in coprolites and quartzites (jasper, chert, flint, &c., § 248). The majority are #Cyrtoidea#, the minority #Sphæroidea# and #Discoidea# in almost equal proportions; a few #Beloidea# (_Sphærozoum_) and #Phæocystina# (Dictyocha) are also found among them. The general morphological character of these Jurassic Radiolaria is very different from that of the nearly related Tertiary and living forms. In general, their siliceous shells are firmer and more massive, usually also somewhat larger, but of simpler structure. The manifold delicate appendages (spines, bristles, feet, wings, &c.) which are so richly developed in the living SPUMELLARIA and NASSELLARIA, and are also well shown in the Tertiary species, are entirely wanting in the majority of the Jurassic Polycystina. The #Sphæroidea# and #Prunoidea# are all simple spherical or ellipsoidal lattice-shells (Monosphærida); concentric lattice-shells (Polysphærida) are entirely wanting. The #Cyrtoidea# are, for the most part, devoid of radial processes or basal feet (Eradiata); triradiate and multiradiate forms, such as are found abundantly in the recent and Tertiary formations, are very rare. The large number of many-jointed forms (Stichocyrtida) and of #Cyrtoidea# with latticed basal opening is very striking.

A. The most important work on the Jurassic Radiolaria, regarding which
but little was known prior to the year 1885, is the valuable and in some
respects very interesting Beiträge zur Kenntniss der fossilen Radiolarien
aus Gesteinen des Jura, by Dr. Rüst of Freiburg i. B. (1885,
Palæontographica, Bd. xxxi. 51 pp. with 12 plates). Unfortunately this
important work was issued only when about half of the present Report was
printed off, so that it was no longer possible to include the 234 species
there described in its systematic part. I have therefore elsewhere given
a list of the Jurassic Radiolaria, and at present only make the following
remarks:--Of the 234 species described, the larger half (130) belong to
the NASSELLARIA (#Cyrtoidea#), the smaller half (102) to the SPUMELLARIA
(38 #Sphæroidea#, 14 #Prunoidea#, and 50 #Discoidea#). In addition, there
are 2 PHÆODARIA depicted, and several spicules which are probably to be
referred to the #Beloidea#. Among the 130 #Cyrtoidea# (of which 2 are
described as #Botryodea#), there are 24 Monocyrtida, 14 Dicyrtida, 22
Tricyrtida, and 70 Stichocyrtida. Just as striking as the predominant
number of the last is the fact that there are only very few triradiate
(9) and multiradiate (4) species found among these 130 #Cyrtoidea#, as
also the large number of species with latticed basal opening;
#Stephoidea# appear to be entirely wanting. The rich material of jasper,
chert, flint, and coprolites in which Dr. Rüst found these Radiolaria, is
derived for the most part from the Jurassic rocks of Germany (Hanover,
South Bavaria), Tyrol, and Switzerland (compare § 248).

{clxviii}B. Jurassic Radiolaria from Italy, also found in jasper, which
are closely related to the forms from Germany and Switzerland described
by Dr. Rüst, were made known so long ago as 1880 by Dante Pantanelli in
his treatise I Diaspri della Toscana e i loro Fossili (Rome, 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 appears 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" (Rüst, L. N. 51, p. 3). Unfortunately 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 #Sphæroidea# and 9 #Discoidea#) and 17 NASSELLARIA (4
#Stephoidea# and 13 #Cyrtoidea#); many of which seem to be identical with
the forms more accurately described by Dr. Rüst (compare p. 1762).

C. From the Lias of the Alps and more particularly "from the lower
Liassic beds of the Schafberg near Salzburg," Dr. Emil von Dunikowski in
1882 described 18 species of fossil Radiolaria (L. N. 44, pp. 22-34, Taf.
iv.-vi.); most of these are #Sphæroidea# and #Discoidea# and appear to
have been more or less altered by petrological changes; their spongy
structure is probably secondary.

D. Cretaceous Radiolaria have been hitherto described only in very small
numbers; quite recently Dr. Rüst 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
#Sphæroidea#, 1 #Discoidea#, 1 Dictyocha, and 3 #Cyrtoidea#.

E. Triassic Radiolaria have recently been discovered by Dr. Rüst in
chert, but have not yet been described.

244. _Palæozoic Radiolaria._--The number of Radiolaria which are known from the Palæozoic or Primary formations is much less than from either the Mesozoic or Cainozoic periods. Here, however, the investigations of recent times have yielded important information; a few species, at all events, of Polycystina (mostly #Sphæroidea#) are now known from various Palæozoic 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 Palæozoic 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. Rüst
regarding the occurrence of Radiolaria in all the Palæozoic formations
have not yet been published. From conversations with this estimable
palæontologist I have learned, however, that he has pursued his fruitful
investigation of the Mesozoic quartzites (§ 243), and has met with no
less success in the case of similar Palæozoic 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
(#Sphæroidea#) and NASSELLARIA (#Cyrtoidea#) {clxix}exhibit very
primitive structural relations. The occurrence of fossil Polycystina in
the Carboniferous formation of England has been incidentally mentioned by
W. J. Sollas:--"In the carboniferous beds of North Wales pseudomorphs of
Radiolaria in calcite occur, along with minute quartz crystals" (Ann. and
Mag. Nat. Hist., 1880, ser. 5, vol. vi. p. 439); and in the siliceous
slate-beds of Saxony Rothpletz has shown the existence of a few
#Sphæroidea# (Zeitschr. d. Deutsch. Geol. Gesellsch., 1800, p. 447).

245. _Abundance of Radiolaria in the Various Rocks._--The relative quantity of well-preserved or at all events recognisable Radiolaria in the different rocks is very variable. In this respect three different degrees may be distinguished, which may be called shortly "pure, mixed, and poor" Radiolarian formations. The _pure_ Radiolarian rocks consist for the greater part (usually much more than half, sometimes even more than three-quarters) of closely compacted often calcined masses of siliceous Polycystine shells. To this category belong the pure Miocene Polycystine marls of Barbados (§ 246), the Tertiary Polycystine clay of the Nicobar Islands (§ 247), and the Polycystine quartz of the Jura (§ 248). All these pure Radiolarian rocks may be regarded as fossil Radiolarian ooze (§ 237), and are certainly of deep-sea origin, having probably been deposited at depths greater than 2000 fathoms. Their palæontological character also is in favour of this view, for the abyssal Osculosa (§ 235) are more abundant and richer in species than the pelagic Porulosa (§ 233). The elevation of this deep-sea layer above the surface of the sea appears to have taken place but seldom; it has only been observed on a large scale at Barbados and in the Nicobar Islands. The _mixed_ Radiolarian rocks are much more common; they were probably deposited at much less depths, or perhaps are not true deep-sea formations at all. The siliceous shells of Polycystina always constitute less than half (sometimes less than one-tenth) of their mass, and are less prominent than other siliceous remains (Diatoms), or calcareous remains (Foraminifera), or in some cases than the mineral constituents (pumice, &c.). To this group belong many of the above-mentioned Tertiary marls and clays (especially the Mediterranean Tripoli), also many flints, cherts, and other quartzites from Mesozoic strata (especially from the Jura), and probably also some palæozoic quartzites. The marine ooze from which they have originated may have been deposited at very various, even at slight, depths of the ocean. Formations _poor_ in Radiolaria, which contain only a few species of SPUMELLARIA and NASSELLARIA mingled with other fossil remains and mineral particles, occur in all formations and are probably very widely distributed. Further careful examination of thin sections (especially of coprolites) will yield here a rich harvest of new forms. Both the mixed and the pure Radiolarian formations may be divided according to their petrographic characters into three groups, which, however, are connected by intermediate varieties--(1) soft, chalky marl (§ 246), (2) plastic clay (§ 247), and (3) hard, flinty quartz (§ 248).

{clxx}246. _Radiolarian Marl._--Those soft, friable rocks, which contain a large quantity of calcareous matter, but consist for the most part of the shells of SPUMELLARIA and NASSELLARIA, are called Radiolarian or Polycystine marl, often more correctly Polycystine tripoli; the best known example of them is the chalky marl of Barbados in the Antilles (§ 242). The Tertiary mountain system of this island, which in Mount Hillaby rises to a height of 1147 feet and includes about 15,800 acres, consists almost exclusively of these remarkable masses of rock. Most of it appears as a soft, earthy, often chalky marl, with a considerable but variable amount of calcareous matter. Those specimens, the greater half of which is composed of well-preserved siliceous shells of Polycystina, and which contain little lime, approach the tripoli and "Kieselguhr." Those specimens, however, which contain the largest amount of calcareous matter resemble common writing chalk in consistency, and consist for the most part of shells of Foraminifera and their fragments; of these there are only few species but large numbers of individuals, generally in small fragments with a fine calcareous powder between them. They may be regarded as fossil Globigerina ooze (§ 238). In a third group of specimens from Barbados the quantity of fragments of pumice and other volcanic matters predominates; the amount of clay is also very considerable; these deposits pass over partly into actual clay partly into volcanic tuff. A fourth group exhibits relations to a coarser often ferruginous material, and although the shells of Polycystina are less abundant in it, still it may be shown to be composed largely of fragments and metamorphosed remains of them. The colour of this deposit, which in some places passes over into sandstone, in others into clay, is usually rather dark, grey, brown, sometimes red and occasionally black (bituminous). The Radiolarian marls of the first two groups, which sometimes approach the white chalk, sometimes the Kieselguhr, are grey, or even pure white (see note A). The same constitution is exhibited by the yellowish or white, very light and friable Polycystine marls of Sicily, which in Caltanisetta approach the chalk, and in Grotte the Kieselguhr. In Greece (Ægina, Zante, &c.), on the other hand, they pass over into plastic clay, and the same occurs in the Baden marl of the Vienna basin. In North Africa, however, on the Mediterranean shores of which the Radiolarian marl seems to be very widely distributed (from Tripoli to Oran), it sometimes becomes changed into actual firm polishing slate, sometimes into pulverulent Kieselguhr or tripoli (Terra tripolitana, see note B). Most of these Radiolarian marls appear to date from the middle Tertiary (Miocene) period, and to be deep-sea formations.