360 



RET. A. W. BOWS OX THE 



numbered 106, 107, 172, and of these the section of 107 is full of 

 dark lines, apparently lines of line dust, crossing and recrossing the 

 crystals, 



Sihcified Wood. — Some few specimens of siliciSed wood occur in 

 the drift; those I have are numbered 116, 117. 174; of these 11(5 

 was kindly examined for me by Prof. Williamson, of Victoria 

 Iniversity, and he considered it to be conilerous and probably 

 Jurassic : 117 is a section of a much larger fragment, and shows 

 very clearly the medullary rays, separated by interlacing woody 

 fibre. 



Sandstones. — These occur in much greater abundance in the drift 

 than any other rock except the flint. The specimens which I have 

 selected are numbered 118 to 140 and have been for the most part 

 struck off large blocks much rounded and polished. Some of these 

 blocks are very large, one measuring 5 ft. 9 in. X 3 ft. 6 in. x 2 ft., and 

 as this lies deeply imbedded in the soft clay ground, it must be nearly 



4 ft. 6 in. in width. This mass was dug out some few years ago and 

 dragged to its present position, where it forms part of a farmyard wall 

 within a mile of Felstead : the specimen is numbered 132. In the 

 village of Pelstead there is a raised way, the outside border of which 

 is formed of no less than thirty-six large blocks of sandstone, two of 

 limestone, and one of dolerite : others stand near farmhouses 

 and blacksmiths' forges and in front of inns. The majority of 

 them are ferruginous, some being highly so : a fair number are 

 completely siliceous : as a rule the)- are very fine-grained, some 

 being specially compact and none that I have found being really 

 coarse. They are also, with two or three exceptions, entirely un- 

 fossiliferous. I am indebted to Mr. H. Keeping, of the AVood- 

 wardian Museum at Cambridge, for having examined them, and he 

 considered them to be for the most part Carboniferous Sandstones, 

 two or three being pebbles of Millstone Grit ; the exceptions, which 

 are fossiliferous, are first a block of hard and compact reddish-yellow 

 sandstone, no. 128, containing casts of Aviculoptcten and some small 

 fragments of crinoid stems ; and next two large blocks of a greyish- 

 yellow sandstone, no. 1 23. one measuring 3 ft. 3 in. X 2 ft. 6 in. x 1 ft. 



5 in. One of these forms part of the raised way in the village, and 

 consequently I cannot do more than just chip it. The other and larger 

 block lies in a farmyard, and I have therefore been able to examine 

 it : I have found in it fragments, but only fragments, of Pecten 

 orbicularis; this sandstone has, however, a peculiar glazed surface 

 when fractured, and Mr. Keeping recognized it as being of the same 

 character as that which occurs in the Lower Greenland in Lincoln- 

 shire, and which he has described and figured in his paper on the 

 Lincolnshire Xeocomian ( Quart. Journ. Ofeol. Soc. vol. xxxviii.). I 

 have also found two or three smaller boulders of a glauconite sand- 

 stone, which probably belongs to the same series, in addition to 

 these, there are here and there boulders of a rather soft argillaceous 

 sandstone, but, so far as I have yet discovered, these are quite 

 unfossiliferous ; and boulders of the coarse conglomerate known as 

 "Hertfordshire Pnddingstone " are fairly abundant, some of them 



