526 Revieivs — Geology and Forestry. 



evidence is wanting as to the original extension of the limestone in. 

 individual districts ". While mostly of Middle Devonian age, 

 certain parts of the limestone "may represent the Cuboides-stage 

 of the Continental Upper Devonian". The higher portion of tlie 

 Upper Devonian is represented by the Goniatiies-mtumeacens-stage at 

 Lower Dunscombe. The names of the Devonian fossils collected 

 during the course of the survey have been revised by Dr. Ivor 

 Thomas. 



It is noted that in the Lower Culm Measures the chert-beds seem 

 to be developed on different horizons, "immediately beneath the 

 J^osidonorm/a-heds and perhaps to some extent intercalated with 

 them," and at lower positions down to the local base of the series. 



The interbedded and intrusive igneous rocks of the Devonian and 

 Carboniferous are described by Dr. Flett, who calls attention to the 

 occurrence of spilites showing excellent 'pillow-structure' near 

 Bickington. Sclialsteins and quartz-keratophyres are likewise 

 described. The intrusive rocks include diabases, proterobases, picrite, 

 and portions of the Dartmoor granite, with felsites. Accounts are 

 given of the contact alteration produced by the diabase sills, and of 

 the metamorphic aureole bordering the granite. 



The Permian rocks, including the basalt of Dunchideock, and the 

 Trias are described by Mr. Ussher, and the Upper Cretaceous by 

 Mr. Reid, who has naturally relied on Mr. Jukes-Browne for most 

 of the particulars.^ In transcribing " his account with a few 

 modifications", it would have been well to have used inverted 

 commas for the quotations, and to have inserted the modifications 

 within brackets. The Eocene and Oligocene deposits are described by 

 Mr. Beid, who gives his reasons for separating the Eocene, and 

 presumably Bagshot, gravels of Haldon from the similar gravels at 

 a lower level in the Bovey Basin. Much has yet to be done in 

 following the connecting links between tlie Bagshot gravels of Black 

 Down near Portesham in Dorset and the South Devon deposits. 

 Details are given of the Bovey Beds, with list of plants, the 

 majority of which have been determined by Mr. and Mrs. Keid to be 

 " identical with species found in the well-known brown-coal deposits 

 of Germany. These are now generally accepted as the highest 

 Oligocene strata, though certain authorities class the Aquitanian 

 stage as lowest Miocene". 



The remaining portions of the memoir contain accounts of caverns 

 and fissures, river gravels and head, recent changes, water supply, 

 metalliferous deposits, building-stones, clays, lignites, etc. There 

 is one plate of photomicrographs of igneous rocks, and another 

 showing much-weathered Triassic 'sandstone resting on the Budleigh 

 Salterton Pebble-bed. 



II. — Geology and Fohestkt. 

 ^URING the past few years the subject of afforestation has 

 attracted more and more attention, and considerable areas of 

 gathering ground connected with waterworks, as well as some tracts 

 rendered barren and unsightly by tips from mines and quarries or by 



^ Memoir on Cretaceous Eocks of Britain, vol. i, 1900. 



