584 R. H. Chandler—Drift at Bostall Common. 
The granite of Uwet differs considerably from the granites found 
between the Calabar River and the Lyangita in the neighbourhood of 
Uyanga and Ojo ’Nkorimba. The latter recalls the porphyritic 
granite of Itara in containing sphene as an important accessory 
constituent, and, in the presence of a mineral resembling epidote, 
certainly of primary origin, the identification being at present doubtful. 
The rock from the lyangita towards Iwudu contains some quantity 
of a strongly pleochroic green hornblende, and traces of the same 
mineral appear in the granite north of Ojo ’Nkorimba. Well-built 
crystals of brown biotite are conspicuous in all slides examined from 
this part of the district. Orthoclase is the predominant felspar; but 
the rock a short distance south of Uyanga contains large crystals of 
microcline, as does also a specimen collected between the Lyangita and 
Calabar Rivers. The plagioclases, commonly zoned, appear to be 
albite or oligoclase, or both. Large grains of quartz are plentiful, 
and quarts vermiculé is common and characteristic. In some specimens 
tourmaline occurs, but it is very rare. One or two of the rocks haye 
been very slightly crushed. 
The red aplites, which are apparently the latest igneous rocks of 
the lower Akpa Iyefe (for basalt dykes are not seen), consist of an 
ageregate of felspar and quartz, the former mineral slightly pre- 
ponderating over the latter. Micropegmatite, the possible presence of 
which is suggested by the hand-specimen, is found to be but feebly 
represented; a thin, not very well defined rim of intergrowth is, 
however, usual where quartz and felspar meet. A point of some 
interest lies in the composite nature of the felspars; due, either to 
an almost complete resorption of an early generation of the mineral, 
or to a later influx of felspathic material which has partially dissolved 
the pre-existing mineral and embedded the fragments within its own 
substance. 
Aplites also cut the porphyritic granite of Itara (along the valley 
of the Ukpong River). The same rocks, intrusive in hornblende- 
schists, are conspicuous in a creek running into the Agboyip River, 
itself a tributary of the Ukpong; and to the north of the village of 
Awi (south of Nsan), ete. 
In distinguishing between the granitic gneisses and the later 
granites mention may be made of the fact that, as a systematic 
investigation of the alluvial deposits proves, monazite is characteristic 
of the former. 
II.—On a Drirr at Bostatt Common, NEAR PLUMSTEAD. 
By R. H. Cuanptzr. 
APPING a small patch of London Clay on the highest part of 
Bostall Common (284 O.D.'), there is a ‘drift’ that presents 
peculiarities identical with part of the gravel on Shooters Hill 
(2 miles distant) at 424 O.D.* 
The gravel at Shooters Hill has been frequently described, so 
1 Both these heights are the highest points of the drift. 
