44 Reports and Proceedings—Geological Society of London. 
The well-known pisolitic iron ore of Tremadoc is shown to follow 
the line of this fault, and is thought by the author to be of the nature 
of a metasomatic veinstone. 
Direct evidence of overthrusting has been got from a study of the 
graptolite-bearing Llandeilo rocks of Tyddyn-dicwm, which have been 
exposed in two artificial trenches dug for the purpose; and the 
distribution of the andesitic volcanic. series in lines of detached 
lenticles among the Grey Slates is described as evidence of a similar 
reduplication of the newer series of the north - eastern district on 
a more extended scale. 
The actual lines of major thrust-planes, other than the Penmorfa 
Fault, have not been discovered; but, from the broad-spreading 
character of the sills of gabbroid dolerite, the author infers that these 
have come in along the thrust-planes. 
The petrogr aphical characters of these quartziferous and hypee iene 
bearing dolerites are not dealt with, but it is noted that the dolerites 
are (1) unaffected by cleavage and faulting; and (2) have meta- 
morphosed rocks which were already cleaved, “cut, and reduplicated by 
the thrust-faulting at the time of their intrusion: in this the author 
joins issue with previous observers in regard to their age. 
The Glacial and post-Glacial accumulations are also described in 
> outline. 
2. ‘On some Small Trilobites from the Cambrian Rocks of Comley 
(Shropshire).” By Edgar Sterling Cobbold, F.G.S. 
The majority of the trilobites noticed in this communication were 
obtained during the progress of some of the excavations referred to in 
the Report of the Geological Excavations Committee of the British 
Association, read at the Dublin Meeting, 1908. 
The specimens were derived from the Olenellus Limestone of Comley, 
and from the Grey Limestones which intervene between that horizon 
and the Conglomeratic Grit yielding a Paradoxides fauna. 
The author notices the occurrence of Microdiscus lobatus, Hall, 
M. speciosus, Ford, WU. helena, Walcott, and Ptychoparia (?) attle- 
boroughensis, 8. & F. He describes eleven species, apparently new, 
which he refers to the genera Itcrodiscus, Ptychoparia, Micmacca (?), 
Agraulos (Strenuella), “Anomocare (three species), Protolenus (two 
species), and two species to a new genus, to which Mr. Matthew’s 
species Micmacca (?) plana may also be referred. 
All the trilobites are represented by detached portions or fragments, 
often mixed indiscriminately, two or three species together, in the 
separate bands of rock; and the author adduces in some detail the 
evidence for correlating certain free cheeks, thoracic segments, and 
pygidia with the various head-shields, so that future workers may 
clearly distinguish between that which is actual fact and that which 
is a matter of inference. 
3. ‘The Rocks of Pulau Ubin and Pulau Nanas (Singapore).” By 
John Brooke Scrivenor, M.A., F.G.S. 
Pulau Ubin and Pulau Nanas are islands set in the eastern entrance 
to the Straits of Jahore, and consist of igneous rocks of considerable 
interest. Pulau Ubin is composed mainly of hornblende-granite, but 
