Carruthers — Secondary Cycadean Fruits. 101 



and drift of the higher ground is a more recent deposit it mnst originally 

 have extended coastwise, and spread over the present low-level clay. 

 It is strange, in this case, that no remnant of such super-position 

 exists, and that the denudation, which must have removed the 

 upper deposit, should have left the lower with such a regular plat- 

 form-like structure throughout so great a range of coast circuit. I 

 am not prepared to say that this could not have been the result of 

 marine erosion, working at a higher level than the present coast-line ; 

 but taking other evidence into consideration it would appear that in 

 this approximately level surface, we have the original surface of 

 deposition, which took place in comparatively shallow water. 

 Wherever the older rocks rise up to more than 100 or 150 feet above 

 the sea level, the coast Boulder-clay "throws out," and instead of 

 following the irregular basement line, and rising of its full thickness 

 with the subjacent formation, it rapidly thins out to nothing, and is 

 lost at a height of 100 and 150 feet above the sea level. 



In the case of the inland deposit of Drift and Boulder-clay on the 

 higher ground of the centre, and west of the country, it is difficult 

 to directly identify it with that on the higher ground of Suffolk, 

 Norfolk, and Bedfordshire. The various levels at which it occurs is 

 remarkable, and can only be accounted for, either on the theory of 

 unequal elevation, or from the whole having been progressively 

 deposited during a submergence, in extent, eqixal to the altitude of 

 the highest drift ; but, as before observed, the general level of the 

 terrace of clay, fringing the coast of Norfolk and Yorkshire on the 

 east, and of Wales and Lancashire on the west, seems to point to an 

 uniformity of age. and to distinguish it from the Boulder-clay and 

 drift occurring at various higher levels, and it is with it, rather than 

 that on the higher ground, that the supposed Glacial beds overlying 

 the Brick-earths and gravels of the Thames valley may possibly be 

 identified. 



II. — On Some Cycadean Fruits fkom the. Secondary Bocks d^ 



Britain.^ 

 By William Carkutheks, F.L.S. of the Botanical Department, British Museum. 



(PLATE VI.) 



TWO of the Gymnospennatous Orders are represented by fruits 

 found in Secondary strata, viz., Cycadece and Conifercs ; ^ no re- 

 mains have been observed, as far as I know of any plant belonging 

 to the Gnetacea.^ There is satisfactory evidence of the existence of 

 Coniferce from the period of the Old Bed Sandstone ; but it is very 

 doubtful whether the Palteozoic fruits and leaves which have been 

 referred to Cycadece have anything whatever to do with that order. 



1 Eeprinted (with some additional notes and alterations) from the "Journal of 

 Botany" for January, 1867. 



2 For an account of the Coniferous Fruits, see Mr. Carruthers' papers in the 

 Geological Magzine, Vol. III., p. 534, Plate XX. and XXI.; and " On Arau- 

 carian Cones," Vol. III., p. 249, Plate XL 



3 Goeppert found a small fragment of what he believes to be an Ephedra in amber, 

 which he has called Ephedrites Johnianus. 



