35 



in one of liis aquaviums. This rotifer lives in a trauspareut and 

 narrow tube, tlirougli whicli the formation of the ova and the 

 development thert'froiu of tlii! young- are plainly seen. This 

 species displays only two ciliated lobes or Avhecls, whereas the 

 Najas and Moliferta display fonr ; nevertheless it is a pleasing 

 object. Tli(> similarity of the Limnias, c(>rat(jphylli, Melicerta 

 rinj^(?ns, and the Tubieolaria Najas. was made plain by diagrams 

 of the three, wliich w<'re beautifully executed on a large scale hy 

 the author, sd as to make the whole subject plain to the meeting, 

 and to afford an excellent example by this kind of illustration. 



Captain MacDakiu then drew attention to some fossil wood 

 from Eastwear Bay, near Folkestone. Although he had on a 

 former occasion shown similar specimens, it was now the 

 l)eculiar mineralisation of this wood that he begged to submit to 

 the notice of the (Society. It occurs in the junction bed between 

 the lower greeusand and gault da}', and is always more or less 

 Avaterworu, being sometimes bored through by teredoes and 

 lather boring shells, it having probably been washed out to 

 sea by some old river flowing from an unknown land, and hav- 

 ing become waterlogged sank to the bottom of a sea that is now 

 the upper bed of the lower green sand, where it is exposed to 

 view as the cliff near Copt Point gives way from time to time 

 before the battering action of the waves. It presents a flattened 

 appearance in comnion with most fossil remains owing to the 

 compression of the overlying rocks. Wonderful as is the train 

 of thought which all this suggests, perhaps still more curious 

 are the changes which have taken place in these specimens, 

 which arc now rather the form of wood than the thing itself, 

 only about 6 jier cent, of carbon remaining, instead of 50, the 

 quantity contained in most woods, the rest, with the exception 

 of 8 per cent, of moistui-e, being mineral matter, and that 

 mineral consisting of 40 per cent, of phosphate of lime. Woods 

 contain a minute quantity of pho.sphate of lime, but here we 

 find an amount equal to that which we might expect in animal 

 remains, bones of animals and fish containing over 50 per cent. 

 of phosphates. The original carbonaceous matter, amounting to 

 perhaps 50 per cent., having dwindled down to 6 per cent. 

 The source of the phosphates is probablj- the highly 

 fossiliferous overlying gault clay, containing numerous 

 spherical bodies sometimes called turtles' eggs, the best ex- 

 planation of these strange fossils being that they arc not turtles' 

 eggs at all, but the shrivelled-up bodies of the Belemnites, the 

 extinct representatives of the cuttle tishes, mIio left their tails 

 behind them in countless numbers, the egg-like part containing 

 40 per cent, of phosphate of lime. By that process (of which 

 v,-Q tind several instances, as the substitution of iron pryritea, 



