Puate 4, 
Fic. 9. Typical nodule from Station 13, September 5, 1899, lat. 9° 57’ N., long. 187° 47’ W., 
Fre. 
1 10; 
dh 
kOe 
14. 
depth, 2630 fathoms. Nodules of this size are very abundant at this station. 
The shape and surface characters are also highly characteristic, so that the 
nodules all look exactly alike. Note the resemblance to the nodule from Station 
4711 shown in Pl. 2, Fig. 4. 
Spherical nodule from Station 173, November 4, 1899, lat. 18° 55’S., 
long. 146° 32’ W., depth, 2440 fathoms, where the spherical shape is the most 
commonly met with. This photograph is given to show the remarkable surface 
characters. he numerous minute, closely-set mammille, giving the surface 
its coarse shagreen-like appearance, are characteristic of the nodules dredged 
at this point, and are to be found on all of them, whatever their shape and size 
may be. 
Section through a flat, slab-like nodule from Station 173. This figure shows, 
not very distinctly, the central core of palagonite, of one of the flat, slab-like 
nodules. The shape of the nodule corresponds to that of the nucleus. 
Section of nodule from Station 175. A nucleus of palagonitic substance as shown 
here is present in all the nodules. The photograph also shows white specks 
of palagonitic substance distributed throughout the thick layer of manganese- 
iron oxides. These specks may be seen specially well on the fractured portion, 
friction having more or less obliterated them on the cut surface. The dense 
compact nature of the layer of oxides is well displayed. 
Section through a small nodule from Station 173. This figure shows the rela- 
tively very large nucleus of the small nodule, sliced and mounted on a slide. 
