1008 
and harder than those of the first type. They have a smooth surface 
and bear a close resemblance to the manganese nodules occurring 
near Sua Lain in the island of Rotti }) in jurassic marls, which 
enclose numerous radiolaria. They are also very much like those 
which were collected in Timor near Mt Somoholle in deep-sea clay 
of presumably triassic age. 
Comparative table of analyses of manganese nodules in red clay. 
Place |E | Stat AS | SAS GELDE Noll Tobee | z4 type 
Depth in | 2600 | 2740 | 2350 | 2335 | 
SiO, | 21.80 | 27.62 | 13.66 |. 20.01 26.5 2.9 
Al,03 6.60 3.10 2.81 (BiB =| 
22.30 23 
Fe,0O; 17.82 | 46.40 | 17.88 2151 
MnO, 39.32 | 25.48 | 14.82 | 38.15 18.3 57.7 
MnO 10.5 
CaO 2.21 2.91 3.53 3.58 1.63 5.6 
BaO 0.35 11.7 
MgO 0.89 127 0.74 | 0.33 0.37 
K,0 | 0.16 
Na,O 1.59 1.1 
NiO trace | trace 0.30 
CoO trace trace 0.17 0.3 
CuO trace trace trace trace 0.13 
Cl (oxyg. aeq) 0.65 
CO, Ree 
H2Oescaping 
above 110° | 11.— | 15.20 | 14.40 | 11.35 11.1 + 15.3 
When broken into halves these nodules look quite compact and 
homogeneous and show no trace of a concentric structure. In 
the last column of the above table the chemical composition of a 
nodule of the second type from Sua Lain?) in the island of Rotti 
is given. It differs much from that of the nodules of the first type. 
These nodules of the second type of Noil Tobee have not been 
examined any further, because JonKER’s notes do not tell us whether 
1) Ref. 12 p. 326, 393; 2 p. 61 and 9 p. 1064. 
3) The large percentage of BaO accounts for the high specific gravity, 
