THE GEOLOGY OF BERMUDA. 13 
trasts strongly with the high dips observable in the drift-rock on the 
Main Island in the vicinity of Hamilton. Near the south end of Ire- 
land Island I observed a stratum of almost perfectly unconsolidated 
sand abounding in shells. In the lower layers of this sand the shells are 
of marine species. In the uppermost layer the shells are those of land 
snails. The stratum is overlain by ordinary drift-rock. The layers 
containing marine shells attain an elevation of about 15 feet above the 
water. In spite of the lack of consolidation of this stratum, I can hardly 
doubt that its lower layers are truly a beach formation, and that the 
transition from marine to terrestrial fossils marks an epoch of elevation. 
A conglomerate evidently of beach origin appears at Stock’s Point, 
the part which remains in situ on the north shore of the Point reaching 
an elevation of about 12 feet; though Mr. J.T. Bartram, an enthusiastic 
self-taught naturalist residing near the spot, assured me that, in a part 
of the bluff which has been removed in quarrying, the conglomerate 
attained a considerably greater altitude. Unquestionable beach-rock 
appears on the north shore of St. George’s near Fort Catherine. The 
rock is at that locality richly fossiliferous. But the most instructive 
localities of the beach-rock which I have observed are along the south 
shore of the Main Island. At various points along that shore the 
beach-rock, more or less fossiliferous, with its characteristic gentle dip 
seaward, forms a gently sloping platform, at the back of which rises a 
low cliff of drift-rock with steep landward dips. The most thoroughly 
satisfactory locality which I observed for the exhibition of the relations 
of the two rocks is near Devonshire Bay. There the beach-rock, which 
forms (as in other localities along the south shore) a platform gently 
sloping seaward, is in places fine-grained and very hard, in other places 
fossiliferous with shells and pieces of coral of considerable size. It is 
surmounted by the usual low cliff of drift-rock with high landward dips. 
Overlying the hard beach-rock of the shore platform, and underlying 
the drift-rock of the cliff, is a stratum of unconsolidated sand, resem- 
bling that observed at Ireland Island, containing marine shells in its 
lower layers and land shells in its uppermost layer. ‘his stratum of 
sand is mentioned by Nelson,* though he seems to have misapprehended 
the character and relations of the fossiliferous beach-rock which under- 
lies the sand stratum. The sand stratum is not recognizable at some 
of the localities on the south shore where the phenomena are in other 
respects as above described. 
* Op. cit., p. 107. 
