Oct. 13, 1870] 
NATURE 
481 
their mineral characters as the lower member. The upper mem- 
ber was shown to be absent from the series in the Long Sleddale 
Valley, its place being represented by ashes and trappian breccias, 
and the middle series, which is usually composed of slaty ashes, 
breccias, and traps, was shown to be greatly modified in type in 
the northern portions of the Lake Country. This middle mem- 
ber of the series is well seen in the country south of Keswick in 
Borrowdale, having its normal mineral character more abounding 
in ashy beds, here woiked for slates. Eastwards from this the 
slaty ashes become less abundant, and in the districts north of 
Ulleswater these ashes were almost entirely absent. In the Vale 
of St. John, porphyry, with comparatively small felspar crystals, 
makes its appearance in connection with the ashy slates. North- 
east from the Vale of St. John th’s porphyry becomes more 
developed, and the ashes are less abundant. At Eycott Hill, 
near Troutbeck station, the lower porphyry also occurs very 
finely exhibited, and containing large crystals of felspar. Near 
the south-east of Carrickfel', a hill largely composed of syenite 
rocks is seen, having a highly crystalline character, and exhibit- 
ing all the features of Diorite. These rocks the authors regard 
as highly metamorphic conditions of the poiphyry above re- 
ferred to or resulting from the action of the syenite of Carrickfell. 
The Caldbeck fells, which form the northern limits of the Lake 
district, have on their northern side the representatives of the 
green slates and porphyries well developed. Here there is an en- 
tire absence of the ashy slates of the middle series, the place of | 
these being occupied bya porphyry similar to that of Eycott Hill. 
This porphyry, however, in the neighbourhood of Roughtongill 
has been so far influenced by the syenite of Carrick, veins of 
which penetrate it, that it now assumes a crystalline form, and 
appears as hypersthene rock. 
The average thickness of the green slates and porphyries, or 
their representatives. in the Lake Country, the authors think does 
not exceed 5,000 or 6,000 feet, a thickness made up of igneous 
products, which in the north of England represent the upper 
Llandeilo series, and a large portion of the Caradoc or Bala group. 
The authors regard the terms green slates and porphyries as 
applied to these rocks in Cumberland and Westmoreland, as inap- 
propriate, since they express merely local conditions, and they 
propose as a substitute the name Borrowdale series. 
On the discovery of Upber Sicurian Strata in Roxburgh and 
Dumfries.—Mr.C. Lapworth. South of the great axis of the lower 
Silurian rocks of southern Scotland, upper Silurians had been 
determined many years ago by Professor Harkness in the neigh- 
hourhood of Kirkcudbright. The author had further detected 
these beds in a very wide strip of country extending from near 
Lockerbie to near Hawick, a distance of forty miles, with a 
maximum width of eight or ten miles. Another large outlier 
had been detected extending from Ernton Hill to Oxnam near 
Jedburgh ; and a further small outlier high up in the Cheviots at 
the head of Kale Water. The rocks in all these districts have 
the facies of the Kirkcudbright series, and the fossils are common 
to all of them. They consist of Graféolithus colonus, Priodon, 
Flemingit and Nillsoni, Rhynconella nucula, Orthoceras tracheale, 
fragments of Plerygotus, Ceratiocaris or Dictyocaris, &c. 
On the Age of the Wealden. —Mr. E. W. Judd. The Wealden 
constitutes one great continuous formation with well-defined 
paleontological characters. As with the ‘‘ Poikilitic” series, 
its beds can only be referred to the different members of our 
established marine classification by violent and arbitrary <ivisiens. 
It must therefore stand as one of the terms of that new system 
of terrestrial classification which Prof. Huxley has shown must 
‘be founded. The epoch of the English Wealden commenced 
towards the close of the Oolitic period ; it continued during the 
whole of the Tithonian (a great system of rocks lately discovered 
on the Continent), and ceased towards the end of the middle or 
beginning of the Upper Neocomian. ‘The passage of the Upper 
Oolite into the Wealden, and that of the Wealden into the 
Upper Neocomian, was each of them gradual. Fresh water 
deposits were formed continuously, but not contemporaneously 
over the whole area of the Wealden, so that in the north-west 
we find only the lower beds represented, and in the south-east 
only the upper ones, while in the central portion we find the 
whole series complete. In the little marine band of Punfield, 
only twenty-one inches thick, we have the representative of a 
portion of the Middle Neocomian, a formation only elsewhere 
found in this country in the middle of the Speeton clay and in 
Lincolnshire. The fauna of the marine band of Punfield has 
yery striking affinities with that of the coal-bearing strata of 
Eastern Spain (which are more than 1,600 feet thick), and espe- 
cially with the middle portion of that series. The North German 
Wealden, which is quite unconnected with that of England, and 
| is probably the product of another river, is not strictly contem- 
poraneous with the latter, for while it appears to have commenced 
about the same period, its duration was considerably less, it 
having terminated the close of the Lower Neocomian. 
On the Physical Geology of the Bone Caves of the Wye.—Rev. 
W. S. Symonds. The author had lately received from Sir J. 
Campbell fossil benes from Arthur’s Caye, on the Great Deward, 
onthe right bank of the Wye, among them the teeth of Eguus 
Sossilis, and a collection had been sent to Prof. Owen, and been 
determined by him to belong to the mammoth, rhinoceros, 
hysena, reindeer, and the great fossil ox. The caves of the 
Wye were at a considerable height above the bed of the river. 
The author considered that the district had been submerged 
below the glacial seas, the clefts of the precipices and the moun- 
tain limestone platform being often covered with boulder clay 
and angular erratic stones. 
On Geological Systems and Endemic Diseases.—Dr. Moffat. 
From continued observation during a long practice, the author 
has ascertained that in a carboniferous district goitre and ancemia 
were prevalent, while these diseases were markedly absent in the 
New Red Sandstone. This he attributed to the presence of iron 
in the one set of rocks, and its complete absence in the other. 
Report of Sedimentary Deposits of River Onny.—Rey. De 
la Touche. The author gave an estimate of the rate of accumu- 
lation of these deposits from a series of observations. 
Notes of a Recent Visit to the Great Tunnel through the Alps 
and of several points of Geological Interest suggested by the Con- 
ditions of the Works in the present nearly complete state.—Prof. 
Ansted. The operations of the tunnel involved a direct cur 
through a series of rocks on a line at a great depth below the 
surface. At the middle of the tunnel there is 5,400 feet of rock 
above it. Observations on physical phenomena have been made 
throughout the progress of the works. The temperatures at 
various distances and deptls haye been recorded. Borings 10 
feet into the rock were made at intervals of 500 metres, and the 
temperature determined at their extremity. The last observation 
made in his presence was 20,342 feet from the south end of the 
tunnel, and 5,000 feet from the surface. The temperature 
shown was 80°5° F., exhibiting an increment of 1° F, to about 
100 feet. Before the value of these observations could be 
ascertained, the mean annual surface temperature and the 
depth of the permanent temperature lines must be deter- 
mined. On the 3Ist of last month (August) there remained 
2,000 out of 40,000 feet of rock to pierce ; as the operations pro- 
gress at the rate of 500 feet per month, the tunnel may be ex- 
pected to be completed by the end of the year. 
On some Points in the Geology of Strath, Isle of Skye.—Profs. 
King and Rowney. The authors entered into a minute descrip- 
tion of the rock structure of the district, from which he drew the 
following conclusions :—That the ophite of Skye is an altered 
rock of the Liassic period ; that it possesses the same microscopic 
features as the ophites of earlier geological ages, occurring in 
Canada, Connemara, and elsewhere ; and that igneous action, 
developing a granitic rock, and producing decided metamor- 
phism in an adjacent deposit, has operated at a later geological 
period in Skye than in any other part of the British Islands. The 
authors further maintained that all the features of the so-called ° 
organism, Loz002 canadense, had been detected by him in the 
Skye ophites, and asserted that the different structures known as 
chamber casts, canal system, nummuline layer, &c., were 
chemical and structural changes, induced by metamorphic 
action. 
SEcTION D.—BIoLocy 
On a@ mode of Reproduction by Spontaneous Fission in the 
Hydroida.—Prof. Allman, F.R.S. The hydroid in which the 
phenomenon which formed the subject of this communication 
had been observed is a campanularian, which in the general 
form of its trophosome comes near to Obelia dichotoma. Since 
however no gonosome was present in any of the specimens 
collected, it was impossible to assign to it a systematic position 
otherwise than provisionally. The remarkable physiological 
act by which it is distinguished, associated as this is withan 
important morphological character, would seem to indicate a 
distinct generic rank, and the author accordingly suggests for 
it the provisional generic name of Schizocladium. 
