Reviews—Lower Paleozoic Fossils of Burma. 225 
many substances of vital importance either for or in connexion with 
the production of munitions of war we should have allowed ourselves 
to be entirely dependent on foreign sources. Tungsten is a case in 
- point. Practically all the ore is produced in the British Empire, yet 
it was all shipped to Germany and worked up there. The country 
is, however, now awake to the danger of allowing key industries to 
be entirely in hands which might become hostile. Another urgent 
reason for making the most of resources actually in the country is the 
necessity for restricting our imports as much as possible. Intelligent 
prospecting might bring to light mineral ores from which might be 
produced many chemical substances at present imported and fast 
growing scarce. 
All the volumes follow very similar lines. The chemical composi- 
tion and physical properties of the minerals supplying the substances 
in question are described very briefly; this section might with 
advantage have been expanded so as to make the identification of the 
minerals easier for those not skilled in the subject. A section 
follows on the commercial uses, with statistics, and the method of 
treatment. The mode of occurrence is then discussed, and -the 
principal mines are described in some detail. The list of localities is 
not exhaustive: possibly none were included which were not repre- 
sented by specimens in the Museum in Jermyn Street. 
Of the substances dealt with, tungsten and manganese are largely 
used for alloying steel, the former having also an extensive use for 
the filaments of incandescent electric lamps; barytes is required in 
the preparation of white paints and for wall-papers, while witherite 
is the principal source of barium compounds; gypsum furnishes the 
familiar plaster of paris, and celestine and strontianite are the sources 
of the strontium used in sugar refining. 
Il1.—Lowerr Patmozorc Fosstts or Burma. 
SuerpLeMENTARY Mermork on NEW OrDovicIaAN AND Siturran Fossixs 
FRoM THE NortHEerN Swan States. By F. R. Cowper Reep. 
Paleontologia Indica, n.s., vol. vi, Mem. 1, viii + 98 pp., 12 pls., 
1915. 
(Y\HE memoir to which this is supplementary was published in 
December, 1906, under the title The Lower Palgozoice Fossils of 
the Northern Shan States, Burma, by F. R. C. Reed, with a Section 
on Ordovician Cystidea, by F. A. Bather. In that memoir fossils 
were described from the Naungkangyi and Nyaungbau Beds of the 
Ordovician, and from the Namhsim and Zebingyi Beds of the Silurian. 
From those beds further fossils are now described, but the chief 
interest lies in those from two fresh sets of beds which are, on their 
evidence, referred to Lower Silurian and Middle Ordovician. 
_ The stratigraphical succession, from above downwards, is as 
follows. Sizurran: Zebingyi Stage, transitional to Devonian ; 
Namhsim Stage, consisting of the Upper or Kénghsa Marls, with 
Phacops shanensis, correlated with Lower Ludlow, and the Lower 
or Namhsim Sandstones, with Phacops longicaudatus, var. orrentalis 
and Lllenus namhsimensis, n.sp., correlated with Wenlockian; and the 
DECADE VI.—VOL. III.—NO. V. 15 
