354 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 7, 



and thus caused the long and shallow mark. A heavy slow-walking 

 animal, like a Tortoise, with an irregular gait, on wet sand, it is pro- 

 bable may have caused the track. This creature must have been of 

 immense size, even larger than the Chelichnus Titan of Sir William 

 Jardine, and for a provisional name I would propose to call it 

 Chelichnus ingens. 



Before concluding, I may add that Mr. Rhodes, the proprietor of 

 the quarry where the specimens were found, not only presented the 

 original slab to the museum of the Manchester Geological Society, 

 but he took a plaster-cast of them, which he is desirous of presenting 

 to some public institution. 



2. On the Lignite Deposits o/Bovey Tracey, Devonshire. 

 By Dr. J. G. Croker. 



[Communicated by the President.] 



(Abstract.) 



The author first described the physical features of the basin, sur- 

 rounding the junction of the Teign and Bovey Rivers, in which these 

 beds of Hgnite and their associated clays (used in pottery) are found. 

 The lignite-beds come to the surface at Bovey Heath towards the 

 north-western margin of the basin ; they underlie towards the south- 

 east about 1 1 inches in the fathom, and are covered by clays and 

 gravels ; their vertical thickness is about 100 feet. In the upper 

 portion of the lignitic series are several (five and more) beds of 

 loose lignite, covered and mixed with variously-coloured clays and 

 granitic detritus ; a ferruginous sandy clay, 9 feet thick, succeeds, 

 which is followed downwards by ten beds of " good coal " or lignite, 

 separated by bluish clay-beds, and worked for fuel. 



Fir-cones, referable to the Scotch fir {Pinus sylvestris), have been 

 found in one of the uppermost layers of loose lignite. Large flabel- 

 liform leaves also are represented by fragments 2 feet long and 

 20 inches wide in some of the higher beds, together with tangled 

 masses of vegetable remains. In the second and fourth beds of good 

 coal (the latter about 80 feet from the surface) the lignite abounds 

 with the little seeds lately described as Folliculites minutulus by 

 Dr. Hooker in the Society's Quarterly Journal*. The lignite gene- 

 rally is composed of compressed coniferous wood, and retin-asphalte 

 is locally abundant. 



The Bovey Basin is about 60 feet above the sea-level, and was 

 almost a swamp until it was drained within the last ninety years. 

 A peat-deposit, in which fir-timber is found, covers the lignites to- 

 wards the south. 



The author also referred to the extensive denudation that the 

 district has undergone, and pointed to the Dartmoor granitic tract as 

 the source of the clays of the lignitic deposits. He also noticed the 



* vol. xi. p. 566. 



