296 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 22, 



is to be seen on the north side of the Bay of Melliha, where a bed of 

 red vegetable soil from 4 to 5 feet thick, with subangular fragments 

 of the parent rock, exists in a sheltered part of the bay a little above 

 the sea-level, and is overlain by irregular beds of red earthy sand 

 and soft calcareous sandstone, that can be traced to have reached a 

 height of nearly 50 feet, and much more in other parts. 



The sand, for the most part, seems to be an admixture of blown 

 and drifted beach-sand, and to contain minute fragments of sea- 

 shells, and the spines of sea-eggs, the most abundant of all living 

 creatures in the shallows of the sea surrounding the island; and the 

 only entire shells in this debris anywhere are land shells of eccistiyig 

 species, which are common. 



The explanation of such an anomalous admixture of only minute 

 fragments of the marine fauna as a general characteristic, but with 

 entire land shells, although so much more fragile, can only be ac- 

 counted for by regarding it as the result of a huge wave that sud- 

 denly swept over the surface of the island, and was probably ac- 

 companied by a short subsidence. Por the dead land shells, 

 through being filled with air when caught up by such a wave as it 

 rushed over the surface of the land, would, by their consequent 

 greater buoyancy than the fragments of bones and stones and sur- 

 face debris caught up with them, have floated with the silt and 

 lighter matter, and thus have been preserved and finally deposited 

 entire with the more earthy debris, as we find here, and exactly as I 

 found repeated in numerous places on the north coast of Africa, and 

 without any indication of an associated tranquil layer or bed, or 

 any entire marine shell to indicate a subsidence sufficiently long- 

 to have caused a return of the marine fauna to it. As in excavating 

 the new and old naval docks at Malta the same beds of red vegetable 

 earth and fragments of surface debris with land shells were found 

 in caverns and crevices that were broken into at 20 feet and more 

 below the present level of the sea, there seems reason to conclude 

 that the island has not risen again quite to the level it reached pre- 

 viously to this subsidence and wave-overflow from which I presume 

 the debris to have mainly resulted. 



Now I am strong in the opinion that we must give waves of trans- 

 lation their due power and effect in contemplating the origin of some 

 high-level as well as low-level accumulations of similar debris, in 

 which land shells and the bones of land animals alone exist in eon- 

 junction with small unworn fragments of the native rock. "We have 

 had many evidences in the historic and even recent times of waves 

 of the sea having swept over lands adjacent to the coast to heights 

 of 50 and 100 feet during earthquakes, and where sudden but com- 

 paratively small uprisings or subsidences have occurred, as on the 

 coast of Peru and Chili. 



I have previously shovm the improbability of these Malta beds of 

 debris having resulted from any ancient local river, independent of 

 the absence of any rolled pebbles or gravel to indicate it in any 

 manner — or even from land-floods, which, as they generally follow 

 the low lands bordering rivers, would, I consider, have left some 



