564 D. MacMntosh — Dispersion of Granite-Mocks — 



This species differs from T. spinosa in having the deep strongly 

 marked fold formed by a depression of the larger, and the elevation 

 of the smaller valve. The number of the plaits is fewer, and it 

 does not appear to attain a larger size than the specimen figured. 

 This species is common in the Inferior Oolite of Appleby, Brigg, 

 Lincolnshire, but it is difficult to obtain perfect specimens. T have 

 dedicated this species to the Eev. J. E. Cross, M.A., F.Gr.S., who gave 

 me the specimen figured. 



I have presented the specimens figured to illustrate this paper to 

 the British Museum. 



Explanation op Figures op Lower Geeensand Beachiopoda prom Upwaee. 

 Figs. I and 2, — Front and side view of Terebratula depressa, var. unipUcata. 



Figs. 3 and 4. — Front and side view of var. Cantabridgiensis. 



5. — Pallial border of same, showing the central elevation on the ventral 

 valve. 

 Figs. 6 and 7.- — Front and side view of Terebratula Seeleyii, sp. nov. 

 8. — Small example of same. 

 9. — T\xvQe V\evis oi Rhynchonella Crossii, sp. nov. 

 All the specimens are figured of the natural size. 



VI. — On the Dispersion of Criffell Granite and Caldbeck 



Porphyry over the Plain of Cumberland.' 



By D. Mackintosh, F.G.S. 



THE following is a very brief statement of the results of nearly 

 two months' observations on the granitic and porphyritic drift 

 of the north and north-west of Cumberland. 



Derivation and Mode of Dispersion of the Granitic Drift. — From a 

 little to the east of Workington, the south-eastern boundary of this drift 

 crosses the river Derwent, and runs along between Great Broughton 

 and Wyndham Eow, north of Tallantire, by Parsonby, and Torpen- 

 how, in the direction of Ireby; it then winds round the west and 

 north slopes of Brocklebank ridge in a line running south of the Eed 

 Dial and Nether Welton. I have found the granite as far east as 

 Wetherall, and believe it extends much farther, while on the north 

 it approaches, if it does not cross, the Scottish Border. The boulders, 

 most of which have been dug out of the fields,'* occur principally in 

 a sea-coast area reaching as far south as Workington, as far north as 

 Allonby, and nearly as far east as Mealsgate ; though, in thinly- 

 scattered groups, and isolated blocks of smaller size, they may be seen 

 farther to the north and east.^ They rapidly increase in size and 

 numbers towards the sea-coast, or in the direction of Criffell (on the 

 opposite side of the Sol way Firth), and gradually thin out inland 

 until they can no longer be detected. There are comparatively few 

 in the valley of the Ellen, even where other erratics are present. 

 On the ridge to the north-west of this valley, and the part of the 



1 For Kirstone and Kirston, read Kirkstone, in my last article (Geol. Mag. for Oct.). 



*_ The so-called surface-blocks are those which have escaped being buried, or 

 which have been disinterred by farmers. The boulders of granite and other rocks 

 are found principally in the lower Boulder-clay, but they are not absent from the 

 upper. 



^ Nearly all the boulders are more or less rounded. 



