260 Ww. A. E. USSHER ON THE TRIASSIC 
“This gravel resembles in every particular the beds between Tam- 
worth and Lichfield (Warwick) laid down by Murchison as Dolomitic 
Conglomerate.” “ We have no gravel-beds near Caen, nor even near 
May.” 
aM. de Caumont says the Evrecy beds belong to the upper part 
of the New Red Sandstone, and have great development in the 
Cotentin.” 
I have traversed the country on foot from Caen to Evrecy, thence 
to May, and back to Caen without finding any indication of Trias. 
Eyrecy is on the Oolites. 
The locality specified as “near” it may be some miles off, Knipe’s 
map being worthless, except as a general index of the lie of the 
rocks. The note is important as bearing on the probable termina- 
tion of the Trias eastward, and as confirmatory of the idea that the 
sands to the north of Campigny were derived from Triassic sands 
underlying pebble gravels near Kvrecy, and overlying marls towards 
La Mine. 
The foregoing quotations and observations lead to the following 
inferences :— 
First. That the Trias of Normandy is much more variable than 
its equivalent in Devon and Somerset, owing to the greater variety 
of Paleozoic rocks furnishing its materials. For instance, Silurian 
and Cambrian quartzites would afford material for gravels and 
conglomerates ; the further comminution of the same strata with 
their associated slates and schists and Devonian grits &c. would 
produce the sandstones and sands, becoming more or less calcareous, 
and locally exhibiting the characters of a limestone, according to the 
local prevalence of Palzeozoic limestones, as, for instance, the Cam- 
brian limestones of St. Clair, St. Jean de Daie, Meauffe, Bahais, 
Cavigny, Airel, &c., all lying to the south of Carentan. The further 
comminution of schists, slates, shales, and limestones would favour 
the deposition of marls. 
Secondly. The general sequence of deposits appears to be pebble- 
beds and conglomerates, passing into and resting on sandstones, 
generally overlying marls, the latter being locally developed on 
different horizons, or, in other words, the constituents of the Trias 
being interchangeable. 
Thirdly. The relations of the deposits bear some analogy to the 
marls and dolomitic conglomerates of the Mendip area on the one 
hand, and to the feeble traces of Upper Keuper Sandstone in the 
vale of Taunton and elsewhere on the other; but they exhibit more 
successional arrangement than the former, and an excess of the con- 
ditions which led to the deposition of the latter. 
I have hitherto confined myself to the descriptive portion of the 
second proposition; it now remains to show the additional grounds 
which justify the statement that only part of the Upper Keuper 
division is represented in Normandy. These are based on the 
thickness of the deposits, not shown in actual figures, but proved 
by the nature of the district; thus :— 
