45 



GEOLOGICAL REPORT COAST EROSION. 



Since, wbat may truly be called, the great work by Dr. Arthur Rowe. F.G.S., on "The Zones of 

 the White Chalk of the Enjjlish Coasts," published in the proceedings of the Geologists' Association, 

 Vol. XVI,, PhtI H,for J900, there has been comparatively little to record except the Coast Erosion most 

 noticeable at St. Margaret's Bay, where since the six-inch ordnance map of 1H76 was published, no less 

 than 200 feet of the foreshore has be^n washed away. 



One of the old inhabitants remembers about 45 years ago a horse-road extending underneath the 

 cliffs to the Cornhill Coastguard Station about two miles East from Dover. Such a road is dotted on 

 on the six-inch map of 187(J from St. Margaret's to Deal. One of the recently erected houses, near the 

 site of the old Coastguard Station, is a perfect wreck. 



The shiD<;jle bank which was the natural protection of this part of the coast has been gradually 

 carried to the Eastward and not renewed from the West as it was previously to the building of the 

 Admiralty Pier at Dover, which now intercepts the shingle. This effect was observed sofiu after the 

 Pier was built more than forty years age, when the houses at the East Cliff, Dover, would have been 

 swept away if the sea-wall had not been built at a great cost for their protection. 



The shingle does not pass round the Admiralty Pier. The gravel sheet found in the Bay is a 

 subangular rivt-r-gravel and quite different from the spherical shinglo of the beach. This subangular 

 gravel sheet is quite compact like a macadamised road and covered with sand or silt, making an in- 

 different holding ground for ships' anchors. 



Another effect of piers built out at right argles to the shore line of the Channel is that the waves 

 running parall^-l to the coast j^re turned round on to shore in like manner to a cylindrical ruler rolling 

 down a sloping deck, which on catching any obstruction, is retarded at one end and deflected round the 

 corner. The waves for a similar cause attacking the coast to the leeward of the obstruclion. 



The set of the currents along the c<iast has also an impottant effect on the movements and 

 accumulation of the shingle or denudation of the coast, and its consequent erosion. 



J. GORDON McDAKIN. 

 13, Esplanade, Dover. 



REPORT ON MARINE ZOOLOGY OF WHITSTABLE BAY 

 FOR THE YEAR 1901. 



There have been no phenomenal tides, winds or trosts to leport. 



NOTE ON THE PROBABLE CAUSE OF THE COMPARATIVE SCAEOITY OF FISH. 



During the past year soles have been fairly plentiful in the estuary of the Thames, owing, probably 

 to the exceptional weather throughout the summer; but the quantity of fish caught in this locality for 

 some years past has been very scanty compared with the yield at a period within the recollection of 

 most of the fishermen ot the present day. 



Not luany years ago sprats came into the.-e waters in such numbers and with such regularity as to 

 warrant considerable outlay by the men in pioviding themselves with the proper nets for this particular 

 fishery, which was then an important and profitable industry. Now, alas, " stowboat-gear," as the 

 tackle was called, has quite disappeared from the Kent side of the estuary. Bass also came into the 

 bay in shoals, and were captured with a trawl net, while now only a few f lequent our sh' re at certain 

 places where they are taken with the hook. The present absence or comparative scarcity of these and 

 other species of fish which were once plentiful in this neighbourhood may, perhaps, be traced to the 

 disappearance of large banks of Zostera marina which existed on the shore off Seasalter down to within 

 the last 30 or 40 years, extending seawards for not less than a mile below high water mark. 



buch a forest uf waving vegetati'in afforded shelter to innumeralile annelid.^, entomotraca, 

 znophytes, and the smaller gasteropodous mollusca, as well as to the ova and youLg fiy 'f many fishes. 

 Thus it became the ft-eding and spawning ground of many of the larger species, until it was found 

 convenient to remove the sandy silt in which the "'sea-grass" fliurished for the purpose uf ballasting ships. 

 Thus the Zustera beds were destroyed, and the fish no longer frequent the shore which has been 

 denuded of the vegetation which afforded them shelter and fuod. 



ON THE OCCURRENCE OF CREPIDULA IN WHITSTABLE BAY. 

 CrepiduJa is a genus of molluscs of the family Calyptrieid/e, of which family the type-genus 

 Calyptrsea (cup-and-saucer limpet) and PHeopsis (bonnet limpet) have representative species in J^ritish 

 waters ; but it is believed thnt. hitherto, Crejndula has not been known as a permanent resident on our 

 shores, being, as it was thought, confined to warmer regions. Within the last three or four years 

 Crepidula/ornic'ita has been discovered attached to stones and shells in Whitstable Bay, and has 

 recently been observed in considerabln numbers; which fact, together with the circumstances that 

 many of the older specimens bear two or three younger generations upon the shell of the animal first 



