Meeting of the Cotswold Cluh. 373 



was so restricted tliat Dr. Wright was constrained to compress within 

 the limits of half an hour an address which needed more than double 

 that time for its due elaboration. The lecture was illustrated by 

 excellent and beautiful sections and figures. The author commenced 

 by saying that this subject had long occupied a place in his thoughts, 

 and that only of late it had gathered such form and consistence as 

 would permit him with confidence to put it forward. He had long 

 been persuaded that without an intimate knowledge and study of 

 the structure of the Zoophyta, it was not possible to comprehend the 

 incalculable importance of those obscure creatures in the seas of 

 ancient and modern times. He briefly described the anatomy of the 

 " Sea Anemone " as typical of a large section of these Zoophytes, 

 and pointed out the diiference between those which have no cal- 

 careous skeleton like the Anemone, and those which build coral 

 structures or reefs in tropical seas, the calcareous material whereof 

 they are constructed being derived from the water of the ocean ; and 

 by colonies of these tiny architects working in unison, structures of 

 gigantic proportions are produced. The lecturer then showed how 

 that the reef-building corals can onlj^ live and work in water, having 

 a temperature of from 80° to 82° ; and as that condition is now 

 chiefly found between 30° north and south of the equator, their 

 operations are for the most part confined within those limits : while 

 even in those latitudes where the ocean is traversed by cold currents, 

 there zoophytic life is absent. He then explained that in certain 

 areas of the earth's surface, one portion is subsiding while others 

 are rising ; that observation had shown that the Coral Sea of our 

 time is a vast area of depression, and that the life-conditions within 

 that area being very favourable to the development of Zoophytes, 

 there was a prodigious growth of reef secretion ; that when they 

 built around land it formed a "fringing reef"; when that land 

 underwent a further subsidence, the zoophytic structure became a 

 "barrier reef"; and that when the land became entirely submerged, 

 rings of coral, "Atolls," like Whit-Sunday Island, alone remained to 

 attest the former presence of terra firma. He then explained how 

 the waste of the reef is ground into a fine mud or into a coralline 

 sand, that the calcareous paste coats particles of sand which become 

 cemented around the nucleus, and how by the constant roll and 

 agitation of an ever restless sea these physical conditions lead to the 

 production of Oolitic Limestones which are found around the shores 

 of the coral islands of our own time. Having thus established the 

 fact that Oolitic Limestones are produced under the conditions just 

 described, he proceeded to apply this natural history fact to an 

 explanation of what had not yet been attempted, namely, the genesis 

 of the Oolitic rocks, some of which they had seen that day. He said 

 that the Oolitic series of rocks may be generally described as a 

 succession of argillaceous deposits, as the Lias, Oxford Clay, and 

 Kimmeridge Clay, with interposed beds of Oolitic rock, such as the 

 Inferior Oolite, the Coralline Oolite and the Portland series ; that 

 the coralline theory applied only to the Oolitic Limestones, for the 

 argillaceous deposits have clearly been formed under other conditions. 



