52 NOTICES OF THE MEETINGS [April 4, 
out their close analogy with markings inscribed on triassic slabs of 
sandstones in New Jersey, on which also ripple-marks, shrinkage 
cracks and foot-prints of birds have been observed. The character 
of these ancient impressions may sometimes be seen to vary where 
the rain has fallen obliquely on rippled surfaces, the cavities being 
deeper on the windward and shallower on the leeward sides of the 
ridges formed by the ripple. Casts of rain-prints are seen on the lower 
surface of several sandstone strata. The direction of the rain is 
usually distinguishable, the longest diameters of the cavities being 
all parallel, and their deepest ends all on the same side. The 
markings attributed by Mr. Redfield to hail, are deep, irregular in 
form, and extremely angular in outline ; and the walls are steeper, 
especially at the deepest extremity of the excavation where they 
often overhang. 
The carboniferous rain-prints of Sydney, Cape Breton, observed by 
Mr. Richard Brown, are some of the most delicately sculptured on the 
lamine of shale. In some specimens they are quite separate from 
each other, most of them oval and with distinct rims. Mr. Brown 
remarks that they only extended over a certain narrow zone, disap- 
pearing when the stratum containing them was traced further in each 
direction ; so that they appear to have constituted a narrow belt, as 
might be expected if they were formed on a sea beach. For when 
rain falls on recent mud bordering the Bay of Fundy, impressions 
are only made on one portion of the exposed surface, the upper part of 
the bank (left dry for ten days or more after the highest spring 
tides,) being too hard to receive any imprints, and the lower part 
near the water’s edge being too soft. In some shales from Cape 
Breton, perfect casts are seen projecting from an under surface where 
the drops are few in number, while in another stratum distinct casts of 
a heavy shower are preserved in a fine-grained sandstone which 
presents a warty and blistered appearance. The casts also of small 
cracks, which must have traversed the subjacent clay, stand out in re- 
lief. Together with these memorials of rain are seen numerous 
winding cylindrical cavities, open at the top and precisely resembling 
these now formed by annelids on the recent mud of the Bay of Fun- 
dy. These strata occur in the same series of beds, in which so 
many examples of buried forests occur, with the trunks of trees 
standing erect, and having their roots attached to them. There are 
also numerous rippled sandstones at different levels in the same for- 
mation. 
On re-examining the slab which he brought in 1846 from the 
coal-strata of Greensburg, Pennsylvania, on which Dr. King first 
found impressions of a carboniferous reptile, Sir C. Lyell finds not 
only shrinkage-cracks but a multitude of small tubercles covering 
the surface resembling the casts of rain-prints, and which he can 
scarcely doubt are referable to pluvial action. 
In conclusion, the Lecturer enlarged on the important inferences 
deducible from the discovery of rain-prints in rocks of such remote 
a 
