IO THE DEPOSITS OF THE SEA-BOTTOM. 



little found. At the northwestern coast of Iceland is found the before mentioned specimen no. 129 

 which is remarkable by its containing almost 50 per ct. of carbonate of lime although taken at a small 

 depth, 117 faths, and only ca. 40 km. from the land; great part of this carbonate of lime, to be 

 sure, is found in the shape of fragments of shells and the like; but as numerous Foraminifera are 

 also found in the specimen, I have thought that it ought to be referred to the Transition clay. Un- 

 fortunately this station is exceedingly isolated, and it might of course be of great interest to know the 

 condition of the sea-bottom from this place towards Greenland, and whether the Transition clay or 

 possibly even the Gray deep-sea clay stretches across the Denmark Strait. On the route followed by 

 the Ingolf Expedition from Iceland towards Greenland, i. e. on 65 Eat. N., the Globigerina clay is 

 found midway; but as this route is directly to the south of the submarine ridge, it is probable that 

 the Globigerina clay does not stretch much farther north. 



The Transition clay is generally gray -brown; sometimes it has a more pure, brown colour; 

 but on the other hand it may also be completely gray, specially the specimens situated closest to the 

 territory of the Gray deep-sea clay. As to consistency the Transition clay is sometimes richly clayey, 

 sometimes rather sandy, which latter quality may have its rise partly from mineral ingredients, partly 

 from the larger Globigerinse and other Foraminifera. The amount of carbonate of lime varies from 

 5-23 to 28-59 P er ct -i an d OI course increases more and more, as we get farther from the territory of 

 the Gray deep-sea clay, and proceed to larger depths. 



The Brown Deep-sea Clay found in three places inside the territory of the Transition clay 

 ought, perhaps, to be incorporated with this; it is distinguished by its especially powerful brown or 

 yellow brown colour, while the colour of the Transition clay is more grayish brown; the amount of car- 

 bonic acid is always very small, about 5 per ct. , although two of the specimens were taken far from 

 land, and in the middle of the territory of the Transition clay. Otherwise the Brown deep-sea clay 

 presents no matter of special interest; it was only found south and southwest of Iceland. 



The Globigerina Clay .covers, in the tract of the sea navigated by the Ingolf Expedition, 

 everywhere the parts of the sea-bottom that are deepest and farthest off from the land. According to 

 Challenger the Red deep-sea clay, found in the very deepest parts of the sea-bottom, is not met with 

 in the northern part of the Atlantic north of 40 Eat N., and only on depths of far more than 2000 

 faths; but the specimen taken on the greatest depth by the Ingolf Expedition, is from 1870 faths. 

 Generally the Globigerina clay does not begin till a depth of 1000 faths ; but several exceptions are found 

 from this rule, especially on the ridge stretching from Iceland towards the southwest into the Atlantic; 

 here it is even found on so small a depth as 485 faths. It is never found near the coast; at the south 

 point of Greenland it is met with at a distance of about 140 km. from the Land; and it reaches about 

 as near to the east coast of Greenland and to the coasts of Iceland, as well to the west as to the south 

 and north. It stretches more close to the smaller islands; southwest of the Faroe Islands it is only 

 about 150 km. from the land, and south of Jan Mayen it is found at about the same distance. As a 

 comparison it may be observed that at the western coast of Norway and Spitzbergen the Globigerina 

 clay is in some places met with up to a distance of about 80 km. from the land, and north of Jan 

 Mayen even at a distance of only 30 km. ; in the tropic seas it is often met with at a distance of less 

 than 80 km. from the coasts of the continents, and as a common rule it may be said that the Globi- 



