137 
Fusus Antiquus : Also occurred, though not massed, old 
and young shells free from sea-wear. 
Echinus Drobachiensis : Also occurred in sandy layers, 
grouped, old and young, as these animals are usually found 
to live. 
Balanus Hameri, a species whose component plates seem 
very slightly attached to each other, and speedily fall apart 
after death and disturbance, occurs whole. It was at this 
locality that M. Brongniart noticed the basal plate shells 
adhering to the gneiss rocks, between which the shales are 
heaped. The like were still to be found there. 
In the more amply extended deposits at Bracke, which 
do not rise above a level of 100 feet "above The sea, there 
are enormous accumulations of the shells of Saxicava 
rugosa. Wherever there was a fresh section ready, or could 
be made, it was easy to pick out multitudes of specimens 
with the two valves together. As the ligament of this shell is 
very slight, and the hinge nothing, these pairs of valves 
cannot have suffered either sea wash or any geokinetic 
change of position, or even pressure. 
The great size and the freedom of growth of the Uddevalla 
Saxicava has been long noticed, indicating its life outside 
of such burrows as gave the more modern form its name. 
One may suppose that the shells, growing at liberty amongst 
piles of shells of their ancestors, may well have developed, as 
we see. Both varieties (rugosa and arctica) occur, the latter 
somewhat more rarely. 
At the same place there were found amongst the Saxi- 
cava valves, which form, as it were, the matrix of the deposit, 
many specimens of Astarte borealis, old and young, with 
both valves in juxtaposition, placed vertically with the 
posterior end uppermost, in the position of life. Astarte 
elliptica occurred also in the same condition, though more 
rarely. 
It was at Bracke that Sir Charles Lyell found the balanus 
lifliriAr'i cfill 5>+-f.npliprl f.n flip rnplrs 
