1870. | ETHERIDGE—BRISLOL DOLOMITIC CONGLOMERATE. 187 
this breccia deep under the plain of New Red (below the present 
sea-level) and overlying the coal-measures of the Somersetshire coal- 
pits. At Clevedon and Portishead it now fringes the sea-margin 
resting on Old Red, Carboniferous, and Pennant, whilst at Clifton, the 
Mendip Hills, the north part of the coal-basin, and numerous other 
spots, it occupies intermediate geographical sites, thus clearly 
showing a depression and reelevation of at least 1000 feet. Du- 
ring the whole of this amount of oscillation and accumulation of the 
Keuper marls and sandstones in the deeper portions of the sea, the 
conglomerates were forming along the margins, shallows, and shores 
of the paleeozoic land. These Dinosauria, then, from their place in 
time, or the elevated geographical locality they now occupy (which 
in this case is a measure of time), would appear to have lived during 
the later portion of the deposition of the Keuper; be it remembered, 
however, that we have no proof of the Bunter beds ever having been 
deposited over the Bristol area. There is nothing whatever to 
show that these Dinosauria did not occupy this area, and live 
through the whole of the Triassic epoch. ‘The chief difficulty is 
the realization of the affinities of these reptiles to any prcexist- 
ing forms through the doctrine of evolution—as well as the area or 
province occupicd by them, or from which they may have mi- 
erated. The question becomes one of the distribution of dry land 
during Preetriassic time, and also whether that land was occupied 
by Dinosaurian and Lacertilan types differentiated through descent 
during the lapse of time that occurred or was represented between 
the Paleozoic and Mesozoic epochs. The limited area occupied 
by this peculiar conglomerate over the Bristol district, and the 
paucity of remains occurring in it, added te the fact that those 
found were evidently not deposited during its early deposition 
or history, render it doubly difficult to come to a conclusion or 
even hypothesis as to the probable distribution of these Dinosauria 
in time. 
7. ZootocicaL Contents oR FAUNA or THE Dotomrric CoNGLOMERATE. 
With the exception of a few fossils derived from the Carboni- 
ferous Limestone and Millstone Grit *, upon which the conglomerate 
rests, only a few reptilian bones belonging to two genera have been 
discovered and assigned to the age of the conglomerate. These 
remains were first noticed and described by Dr. Riley and Mr. 
Samuel Stutchbury, of the Bristol Philosophical Institution, in the 
year 1836+, and were then the oldest known Dinosauria in Britain. 
These authors referred them to two reptilian genera Thecodontosaurus 
and Palwosaurus, noticing their Megalosauroid affinities through the 
characters of the vertebrae and femora. Subsequent examination of 
these remains by Prof. Huxley has clearly established their true 
* Spirifera cuspidata. | Chonctes hardrensis. | Cochliodus contortus. 
striata. Productus. Lithostrotion junceum, 
Terebratula hastata. | Psammodus porosus. irregulare, 
t Geol. Trans. vol. vy. 2nd ser. p. 349, 
