282 Proceedings of the Royal Physical Society. 
where as our type-deposit a marine limestone, and name the 
rocks in question from the locality where the marine cal- 
careous type is best seen and most fully developed. I 
propose, therefore, that we should employ the name 
TyroLIAN for the Trias, just as we use DEVONIAN as 
the type form of the strata that were deposited while the 
Old Red Sandstone was being laid down. I should like to 
go further in this same direction. The Lower New Red 
(Dyas, or so-called “ Permian”) also takes on a marine facies 
in the Mediterranean region, being represented there by a 
considerable thickness of marine limestone, which in Sicily, 
near Palermo—the Panormus of the ancients—has yielded 
a most interesting and extensive set of fossils, including 
many Ammonites. I would suggest that the name PANOR- 
MIAN might fittingly be applied to this, the type-deposit 
of the same age as the Lower New Red, Dyas, or “ Permian.” 
So far as we are concerned in the present inquiry, the chief 
point of interest and importance is that the New Red Series 
is represented on the Continent by a thick series of marine 
limestones (the Tyrolian and Panormian Rocks), which fill 
up the later part of the vast chronological hiatus between the 
Carboniferous Rocks and those of Jurassic age. The abund- 
ance and variety of Ammonites in the Panormian, shows 
that we are dealing with the upper part of the intermediate 
series; but as there is just a possibility that the Panormian 
Rocks may represent not only our own Lower New Red or 
Dyas, but also represent in time part of the gap to be 
presently referred to, I propose for the present purpose to 
leave it out of account, and to compute the time with 
reference only to the marine limestone of the Rhetic and 
Tyrolian series. These are said to be “several thousands of 
feet” in thickness; but beyond this vague estimate there 
appears to be well-authenticated measurements of more than 
3500 feet of marine limestone, largely made up of marine 
lime-secreting alge. Taking the same figures as before, 
3500 feet of limestone at 1 foot in 25,000 years, gives us 
87,000,000 years. Again would I remind the reader of the 
enormous biological changes which took place in the interval 
—the development of the Anomodont reptiles from the 
