92 Reports and Proceedings—Geological Society of London. 
difference of age depends on the lesser dip and degree of consolidation 
of the Ijebu Series. In them a few lamellibranchs have been found, 
of no value as regards the determination of the horizon, and some 
plant-remains; in the Lignite Series only undeterminable plant- 
remains. The Benin Sands are apparently unfossiliferous. The 
information regarding the Ijebu Beds has been derived almost entirely 
from boreholes. 
2. ‘“‘The Geology of the Oban Hills (Southern Nigeria).” By 
John Parkinson, B.A., F.G.S. 
_ The country described in this paper comprises some 1,800 square 
miles of the Kastern Province of Southern Nigeria, adjacent to the 
Kameruns frontier. The rocks are crystalline, principally gneisses and 
schists, with later granites, pegmatites, and basaltic dykes, surrounded 
on the north, west, and south by Cretaceous sediments. For 
purposes of description the series is divided under nine headings, 
according to locality and petrographical character; and it is concluded 
that, neglecting the basaltic dykes, two broad groups may be 
distinguished—the one characterized by the presence, the other by 
the absence, of foliation. In the former the foliation tends to be 
lost, giving a passage between types which petrographically are acid 
orthogneisses and granites. 
Observation of the banded gneisses, which are typical of several 
districts, leads to the conclusion that the acid magma is intrusive 
into mica and hornblende schists, and that the banded gneisses are 
composite rocks produced by injection. The orthogneisses themselves 
exhibit many variations; and study in the field shows that the series 
consists of several members, produced by the differentiation probably 
of one magma, which have reached their present positions at different. 
times: that is, they differ slightly in age. At Uwet was found 
a group of phyllites and grits altered into garnet, andalusite, and 
staurolite-schists, and hornfels, with the development of much biotite, 
by an intrusive gneiss; and it is considered as probable, though not 
eapable at the time of absolute proof, that the sillimanite-gneisses of 
the Ekankpa ford, a few miles away, are the result of an extension 
of the same belt of contact-metamorphism, a suggestion which possibly 
might truly include the schists of the entire district. 
. Typical specimens of the granites, pegmatites, and dykes are 
described, and sketch-maps given. 
3. ‘The Crystalline Rocks of the Kukuruku Hills (Central 
Province of Southern Nigeria).”” By John Parkinson, B.A., F.G.S. 
In this paper a short account is given of the crystalline rocks 
found in the Central Province of Southern Nigeria, between the 
Station of Ifon (north of Kenin City) and the Northern Nigerian 
frontier. The rocks fall under two heads—(a) a group of gneisses 
and (6) a group of schists. 
_ The former is considered as intrusive in the latter, and consists of 
varieties of biotite gneisses, often well banded, but this group is 
not infrequently represented by several rocks readily separable by 
mineralogical peculiarities and by intrusion. 
