REPOET ON THE DEEP-SEA DEPOSITS. 
355 
however, more separated, and the surface has a more rugged appearance. The nucleus of 
this mass had probably originally been a fragment of pumice. The dredge and tow- 
nets contained about twenty fragments of pumice, all rounded, and from 0’5 to 2 cm. 
in diameter. Their surfaces were coated with manganese, and in some instances the 
fragments were cemented together by the manganese. 
Station 254, 3025 fathoms. — One manganese nodule, about inches in diameter? 
was procured in the water-bottle, and in the sample of the deposit from the sounding 
tube there were numerous black grains of manganese. 
Station 256, 2950 fathoms. — A few manganese nodules, sharks’ teeth, and pumice 
fragments were obtained in the clay from the dredge. In some instances the sharks’ 
teeth had but a slight coating of manganese, and in others they were surrounded by con- 
centric layers nearly 1 cm. in thickness. One nodule had a nucleus of bone, but most of 
the others had apparently formed around pumice. 
Station 258, 2775 fathoms. — Two small nodules came up, adhering with some clay to 
the under surface of the water-bottle, and in the specimen of clay obtained by the sound- 
ing tube were a good many manganese particles. 
Station 264, 3000 fathoms. — The trawl brought up seven or eight small manganese 
nodules and hardened pieces of the deposit, frequently traversed in every direction by 
worm-tubes and coated with manganese. One or two of the nodules had palagonitic 
nuclei. 
Station 265, 2900 fathoms. — The dredge and tow-nets brought up a large quantity 
of Radiolarian Ooze of a dark colour. Almost the whole of this ooze passed through the 
finest sieves, but in the siftings were several pieces of pumice, and one small manganese 
nodule about 2 cm. in diameter. The nodule had a rugged exterior ; the nucleus con- 
sisted of a yellowish homogeneous substance, penetrated in all directions by dendrites of 
manganese. Under the microscope this nucleus appeared finely granular, and contained 
many Eadiolarian skeletons, but no crystalline particles were observed. This nucleus 
was probably an agglomerated portion of the deposit. 
Station 272, 2600 fathoms. — The trawl and attached tow-nets brought up some 
Radiolarian Ooze, in which was a small piece of basic pumice, and two or three small 
manganese nodules ; in some of the nodules the nuclei were composed of pumice, while 
in others no nucleus could be recognised. 
Station 274, 2750 fathoms. — The trawl and attached tow-nets brought up a quantity 
of chocolate-coloured ooze, and over a peck (9 litres) of manganese nodules, earbones of 
Cetaceans, sharks’ teeth, and pumice fragments. The manganese nodules were ova], 
flattened, or somewhat kidney-shaped, the largest specimens measuring 10x7x4 cm. 
PI. IV. fig. 2 represents a typical specimen ; there were about one hundred more or less 
resembling this one in form and appearance. These nodules are heavier and more massive 
than the generality of those procured at other stations, and they have almost all the same 
