An eminent example is the Silurian limestone of Pole Hill, in New Brunswick, collected by the late Mr. Robb, of the Geological Survey, and referred to in the text. I cannot doubt that the silicate injecting Crinoids and other fossils in this limestone must have been introduced into these when still recent, and the same remark applies to the serpentine filling a coral at Lake Chebogamong, and fragments of corals at Melbourne, in Eastern Canada, and to the similar mineral filling fossils in a limestone from Llangwyllog, in Wales, and in that of Maxville, Ohio. Hunt regarded all these as coming essentially into the same category as regard to general composition and properties. His analysis of the minerals from Pole Hill and Llangwyllog is as follows:-- Pole Hill. Llangwyllog. Silica 38·93 35·32 Alumina 28·88 22·66 Protoxyd of iron 18·86 } 24·12 } Magnesia 4·25 } 6·96 } Potash 1·69 } 1·40 } Soda ·48 } 0·67 } Water 6·91 11·46 Insoluble, quartz ------ ----- 100·00 99·89 These minerals approach in composition to the jollyte of Von Kobell, from which they differ in containing a portion of alkalies, and only one half as much water. In these respects they agree nearly with the silicate found by Robert Hoffman, at Raspenau, in Bohemia, where it occurs in thin layers alternating with picrosmine, and surrounding masses of Eozoon in the Laurentian limestones of that region;[51] the Eozoon itself being there injected with a hydrous silicate which may be described as intermediate between glauconite and chlorite in composition." [Footnote 51: _Journ. fur Prakt. Chemie_, Bd., 106 (1869), p. 356.] In the Welsh specimen the silicate is of a deep green colour, except where oxidized, and though only 3 per cent, of the whole, is sufficient to give it an olive colour and slight serpentinous lustre. In the Pole Hill material, the silicate amounts to 5 per cent, of the whole, and is of a greyish colour. For some further particulars, see my Paper on "Fossils Mineralized with Silicates" (_Journal Geological Society_, February, 1879). * * * * * C. Affinities of Eozoon, etc., with more Modern Forms.