of the leaves of Arthropitys as well as of its stem. Hence it would seem to be a legitimate inference that there is a close relationship between Calamostachys Binneyana and that type of Calamites which is known as Arthropitys. We might, perhaps, without much risk of error, go further than this, and conclude that the one is actually the spore-bearing shoot of the other, but in a case of this kind it is better to keep our inferences well within the range of the facts on which they are based.

EXPLANATION OF THE FIGURES.

PLATE I.

Fig. 1. Transverse section of the axis of Calamostachys Binneyana. a. Carinal Canals.

v. Small vessels at the margin

of the same.

p. pith.

,, 2. Longitudinal section of Axis.

i.p. Inner parenchyma of

Cortex.

h. Hypoderma of Cortex.

A SKETCH OF THE GEOLOGY OF NIDDERDALE AND THE WASHBURN NORTH OF BLUBBERHOUSES. BY J. R. DAKYNS.

In my former communications to this Society on the Carboniferous Rocks of the West Riding, I have said next to nothing about the geology of that part of the country east of Wharfedale, which drains into the Rivers Nidd and Washburn. I propose now to give a short sketch of the geology of this area; but, in justice to Mr. J. Lucas, I must say that much of my knowledge of its geology, especially as regards the thickness of the beds, is derived from his patient and careful investigations.

In the basin of the Washburn and in Nidderdale the Millstone Grit consists of the following members, which are lettered for convenience of reference, as given in the annexed list.

The thicknesses given above have been obtained by taking averages of several measurements in different places.

The annexed section was also kindly given to us by Mr. Newbold, of Eagle Hall, Pateley Bridge. It seems to be identical with one given by Professor Phillips in his "Geology of Yorkshire," which we got from Mr. Newbold's grandfather.

Feet.

30

150

...

...

48

36

21

141

8

6

B

Greenhow Limestone, thickness not known.

This section was given to us as representative of the measures met with in the workings of the Greenhow Hill Lead Mines. Perhaps the best section of these measures is to be seen in Cock Hill Level, I examined both this level and also the California level under Grimwith Fell, and found great similarity in the grit beds of the two levels; but the limestone shales have almost vanished in Cock Hill, being only eight feet thick.

The thin limestone which lies a little above the top of the Underset Grits reminds one of the little limestone met with just above the Grassington Grits in the shaft in Gateup. There can be no doubt that the Underset Grits of Cock Hill correspond in part, if not altogether, to the Grassington Grits. The coal too is certainly the same as one of those met with in the mines on Grassington Moor. I will now point out the position and run of the chief beds.

The three beds of Kinder Scout Grit, lettered a, b, c, in the above list, run along the northern edge of the one-inch ordnance map, 92° S.E., with a northerly dip; but between Beamsley and Blubberhouse Moor, the top turns, owing to the Beamsley anticlinal, and runs north-east, so that the three beds occupy the Washburn Valley from Moyington House to the dams a mile above Blubberhouses. A dirty coal, eight inches thick, was seen near the top of a, at the head of the Deep Gill, along which the Kex Gill or Skipton Road runs, about two miles west of Blubberhouses. Thence the top runs north of Kex Gill Road, and bending round runs north by Rocking Hall to the Washburn above Hoodstorth and east of Pockstones; thence up the valley and across Kitty White's Allotment to the Craven Fault. A thin bed of sandstone overlies it on Kitty

White's Allotment. Elsewhere in the Washburn basin it is succeeded. in order by the lower and upper grits of Follifoot Ridge, the Shell Bed and two beds of the Brimham Grits, viz., the flags and the Brimham Rock proper.

A coal has been worked in the Lower Follifoot Grit near Thornthwaite, where the section of the rock is as follows :

The upper part of the Kinder. Scout Grit appears as an inlier at Thornthwaite, and also immediately west of Dacre and again around Long Scales.

The Shell Bed gives an excellent and invaluable horizon. Its course can be easily seen by reference to the engraved six-inch Geological Maps, for wherever it occurs the words "shell bed" have been printed on the map; but I may shortly state that, running along the upper part of Redshaw Gill, it turns north by Black Sike, runs under Ravenstones Plantation, and thence by the farmhouses Hay Slack, Hoodstorth, Padside Hall and Padside Green, all of which stand on it. It occurs on the south-east side of the Beamsley anticlinal in several inlying and outlying patches, particularly north of Fewston, where there are two shell beds.

The greater part of the Forest Moor is formed of Follifoot Grits, surrounding islands of the shell bed; and east of Blubberhouses an inlier of the Brimham Rock appears.

Immediately south of the Craven Fault we have a regular series of the beds in a synclinal trough, up to the third bed of the Brimham group.

North of the limestone axis of Greenhow Hill the beds of the Kinder Scout Grit occupy the northern slope of Beamsley Moor. Hardcastle and Cross Gill Moors are occupied by the Follifoot Grits. The top of the Kinder Scout Grits runs up from Ashford Side Beck to the Henless Beck, where it is marked by the tesselated limestone.