82 THE OLD RED AND CARBONIFEROUS PERIOD. CHAP. 



is well proved. I am not aware that such a list has been before 

 prepared by any geologist. 



Millstone grit. A hard sandstone rock occupying the position of 

 this grit, lies over the carboniferous limestone of Wickwar; it has 

 not much resemblance to the millstone grit of the north of England, 

 but is more related to the ' Farewell Rock'' of the basin of South 

 Wales. Haematite accompanies it. 



A rock of similar character and relations is found above the great 

 limestone series of Bristol. It is supposed to be nearly a thousand 

 feet thick. On the borders of the Forest of Dean there is a 

 quartzose conglomerate in the same position. On the eastern 

 border of the Warwickshire coalfield the hard quartzose rocks of 

 Hartshill are of the same age; they are somewhat metamorphic. 

 I have not seen organic remains in these rocks : plants might be 

 looked for. 



The genera of vertebrate and invertebrate animals at present 

 recognized in the mountain limestone series of Bristol appear in 

 the following Table. The four principal divisions (including mill- 

 stone grit) contain altogether a very large proportion of the fossils 

 usually found in this group of strata. The distribution of them 

 is also according to the usual observation elsewhere; the greatest 

 number being found in the lower part of the limestone series, and 

 very few in the millstone grit. Only a small number of the generic 

 groups of the corals, crinoids, and fishes of the carboniferous lime- 

 stone is found again in strata of more recent date, but many of the 

 conchifers are repeated. 



