PROCKEDINGS OP OEOLOGIOAL SOCIETIES. 
167 
copi)er, boniite, coi)j)er-glance, cop])er-j)yrites, varieties of galena, zinc-blende, 
uiiignetite, specular u-on-ore, manganese ore, orpinieiit, sulphur, and l)ro\vn-coal. 
The series ot copjier-orcs appears to indicate the existence of considerable masses 
of metallic mineral, probably in lodes or regiUar veins. The lead-ores have the 
appearance of iiaving been taken either from veins of small size, or from near the 
surface of the gTound. 
The specimens alluded to were exhibited. 
2. " On the Veins of Tin-ore at Evigtok, near Arksut, Greenland." By J. AV. 
Tayler, E.sq., F.G.S. 
These tui-veins, of which there are about twenty, extend over an area of about 
1,.500 feet in length by 80 feet in breadth ; and they run in various directions, 
some E. and W., others N.E. and S.W., and others N. and S. They vary from 
10 inches to i of an inch in width ; in the largest veins the tui-ore occupies about 
1 inch of one side of the vein. The veins nearly all occm- in a gieat vein of felspar 
and quartz ; which contains also ores of lead, copper, zinc, ii'on, and molybdena, 
associated with cryolite, fluor-spar, zircpn, &c. 
Specimens froui Evigiok were exhibited, from the Collections of Prof Tennant, 
F.G S., and the Society. 
3. " On the Permian ChitonidiB." By J. W. Kii-khy, Esq. Conimimicated by 
T. Davidson, Esq., F.R.S., F.G.S. 
After having fully noticed the progress of our knowledge respecting the jiateozoic 
Chitons, and those of the Magnesian Limestone in particular, the author described 
in detail the characters of Chiton Lofiusianus, King, and Chiton Hovseanus, Kirkby, 
and a new species, referred with some doubt to Chiton C. {!) cordatus ; also Chiton 
antiquus, Howse, which Mr. Kirkby refers to the subgenus Chitonellus, as well as 
two new si)ecies, C. Ilancoclcianus and C. distortus. The specimens on which all 
these species have been determined have been fovmd in the Magnesian Limestone 
of the neighbom-liood of Sunderland, Durham, and chiefly in that of Tunstall 
Hill. 
The autiior particularly alluded to the great similarity that some of the plates 
of these fossil Cliitons have at first sight to Paiellce and Calyptraa, and recom- 
mended that especial care shoidd therefore always be taken in the determination 
of patelliform fossils. 
The paper was illustrated by fine pencil-drawings by the author. 
4. " On the Vegetable Structm-es in Coal." By J. W. Dawson, LL.D., F.G.S., 
Principal of IM'Gill College, Jlontreal. 
After refening to the labours of others in the elucidation of the history of coal, 
the author remarks that in ordinary bituminous coal we recognise by the unaided 
eye laminre of a compact and more or less lustrous appearance, separated Viy un- 
even films and layers of fibrous antlu'acite or mineral charcoal. As these two 
kinds of material difi'er to some extent in origin and state of preservation, and in 
the methods of study applicable to them, he proceeds to treat of liis subject under 
two heads : — 1st. Tlie structures jireserved in the state of mineral charcoal. This 
substance consists of fi-agments of prosenchymatous and vasiform tissues in a car- 
bonized state, somewhat flattened by pressure, and more or less impregnated with 
bituminous and mineral matters derived from the suiTounding mass. It has 
resulted from the subaericd decay of vegetable matter ; whilst the compact coal 
is the product of subaqueous putrefaction, modified by heat and exposm'e to air. 
The author proceeded (after describing the methods used by him in examining 
mineral charcoal and coal ) to describe the tissues of Cryi)togamous plants in the 
state of mineral charcoal. Among these he mentions Lepidodevdron and Uloden- 
dron, also disintegrated vascidar bundles from the petioles of Ferns, the veins of 
Stigmarian leaves, and from some roots or stipes. He tlien describes tissues of 
Gynniospermous plants in the state of mineral charcoal ; especially wood with 
discigerous fibres and also with scalariform tissue, such as that of Mgmaria and 
Calaiaodendron ; and the author remarks that probably the so-called cycadeous 
tissue liitherto met with in the coal has belonged to Sigillai-ice. 
The next duef headiiig of the paper has reference to stinctures preserved in the 
layers of compact coal, which constitute a far larger proportion of the mass than 
the mineral charcoal does. The laminae of pitch- or cherry-coal, says Dr. Dawson, 
