A. Rk. Horwood—Upper Trias, Levcestershire. 363 
beds the grey bands are bleached out by drainage along the lines of 
more porous beds, since they were covered up. But this cannot 
be so, because they differ in chemical composition and specific gravity 
from the Red Marls, and they alone contain ripple-markings. As to 
the absence of ripples in the red beds, this is natural because they are 
thicker, laid down in water originally deeper where ripples could not 
be made, while in the shallow sandy grey beds (nearer land or super- ~ 
posed in flood-time on submerged mud-banks) they are general. 
An analogy for the grey beds overlying red beds is found in the 
Magdalen Islands, in the Gulf of St. Lawrence, where there are purple 
sandstones with a persistent covering of white sands, decoloured by 
organic acids. A recurrence of this each time would explain the 
repetition of variegated beds. 
Suncracks occur commonly on the surfaces of the Lower Keuper 
marly beds, and in a few cases in the flaggy beds in the Upper 
Keuper Sandstones, testifying to the periodicity of terrestrial surfaces 
and the proximity of land. The association of footprints with them 
proves that the phase was of some duration. Rainprints occur with 
the suncracks, especially in the Lower Keuper in North and South 
Leicestershire, indicating that (as they are numerous and abundant) 
the climate was not particularly arid, since large amphibious creatures 
lived along with plants such as Equisetacew which required excessive 
moisture. A somewhat modified type of climate existed similar to 
that met with in the Coal-measures suitable for the formation of thin 
carbonaceous layers (incipient coal-seams), and if the occurrence of 
bitumen can be attributed to a similar origin (unless it is volcanic, 
for that also may be suggested), though it was undoubtedly drier and 
' less humid, and the sun-rays were not obscured, as it has been 
doubtfully suggested they were in the Coal-measure period. 
The widespread occurrence of pseudomorphs of salt crystals in 
Lower and Upper Keuper suggests that shallow water lay for periods 
’ upon flats that were allowed to evaporate before they were submerged 
again. The preponderance of brine thus indicated, as well as by the 
occurrence of brine in Triassic waters, bears out the old view of the 
saline character of the waters, and justifies the old name ‘‘Saliferous 
Red Marls”. That salt occurs in abundance in dry regions with 
similar pseudomorphs is well known. We need, however, to take 
into account the innumerable other indications that the period was 
one in which water was the prime agent of importance. 
Besides the continuous thick gypsum bed, not far below the Tea- 
green Marls, there are a number of other horizons at which it occurs 
A the Red Marl, as shown by the Crown Hill and other borings. 
It is also found in the Lower Keuper, but here as in the Orton 
Sandstone Group the bands are thinner. As a rule they are 
continuous, and a marked feature is their horizontality. This and 
the thickness of the band near the top make it clear that the gypsum 
was deposited in shallow lagoons liable to be inundated. Its frequent 
association with Green Marl and Skerry suggests it was formed at 
seasons of flood followed by drier periods allowing desiccation. It is 
probable that the reticulated bands and some ball | ‘gypsum are of 
secondary origin, formed by infiltration from above. The nodules at 
