ox TRE GEOLOGY OF BARBADOS. 22 



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Of the }fi/(h-iop7iora^ ^[r. (rrogory remarks that he is not aware 

 of the p;eniis having been previously recorded from the West iudie-<, 

 and that the species is almost certainly new. With this exception 

 he says the assemblage agrees closely with the recent West-Indian 

 fauna, and he sees no evidence of any Pacific intermixture or in- 

 fluence, adding, " the genera are all Atlantic forms, and there is an 

 entire absence of typical Panama genera such as Monti/wra^ Pavonia, 

 and PociUopora (the last of which is known, but very rare, in West- 

 Indian seas)." 



It appears, therefore, that of those which can be identified, more 

 than half are recent species, and the rest are forms which are at 

 present only known from Prof. Duncans descriptions of fossil West- 

 Indian corals *. It is possible, however, that these fossil forms are 

 not so different from recent species as Prof. J)uncan imagined, and 

 that the apparent differences are largely due to their occurrence in 

 the state of casts. 



It will be noticed that two of the species which still live in West- 

 Indian seas occur in the highest part of the island, and that one of 

 Prof. Duncan's fossil forms occurs in the lowest and most recent 

 reefs. From this it would appear that the w^hole succession of reefs 

 is of comparatively recent geological date — a conclusion which 

 agrees with the inferences deducible from the stratigraphical 

 evidence. 



Prof. Duncan, however, regarded as Miocene all the deposits con- 

 taining the corals which he described, and we are consequently 

 compelled to examine the reasons he had for this belief. These do 

 not appear to be very strong, and indeed the follow^ing extracts will 

 ehow that his conclusion is founded solely on the general resem- 

 blance of the corals to species which occur in the European Miocene, 

 and that there are facts which tend to directly controvert his view. 



He admits {op. cit. p. 452) "that the Testacea sent from Antigua 

 with the corals have been stated to belong to the present age." He 

 was aware also that late Tertiary shells and corals occurred both in 

 Jamaica and San Domingo, but he thinks this is not antagonistic to 

 his view, and says : " So with regard to Antigua, Barbuda, and 

 Barbados it is not correct to give the whole islands a Pliocene or 

 post-Pliocene age, because recent and subfossil shells are found in 

 them." In all this, however, he overlooks the fact that the shells 

 in (question have been obtained from all three of the islands men- 

 tioned in actual association with the corals which he would class as 

 Miocene fossils. Now it can hardly be correct to attribute to 

 deposits a Miocene age when all the mollusca found in them are 

 recent species. 



On p. 453 {op. cit.) he admits that " the range, in strata, of the 

 genera of corals is often so great, and the species of remote formations 

 are so frequently closely allied, that theZoantharia form better guides 

 for estimating the external physical circumstances of the regions 

 in which they existed, than for determining the age of strata.''' 



* Quart. Journ. Geol. Soc. vol. xix. (1863) p. 406. 



