Vol. 54.] THE GLOBIG ERIN'iL-MAELS, ETC., OF BARBADOS. 545 



III. The Succession at Bissex Hill. 



The Scotland Beds which form the base of the hill are succeeded 

 unconformably by the Oceanic Series, which shows the usual 

 succession from, chalks to calcareo- siliceous beds and in places to 

 the upper chalks. The red clays, which elsewhere occur overlying 

 the upper chalks, are not present or are not exposed on Bissex Hill. 



Lying unconformably upon either the calcareo-siliceous beds or 

 the upper chalks is a detrital bed which forms the base of the 

 Olnhigerina-meiTls of the hill. It consists of a thin band of 

 Globigerina-TRSul containing many rolled pebbles and small lumps 

 of various parts of the beds of the Oceanic Series, but mainly of 

 the chalks. Inclusions of clay, presumably derived from the beds 

 of the Scotland Series, are also found in it in places. The structure 

 of some of the slides prepared from specimens of this bed indicates 

 that the included fragments fell or were carried into the Glohigerina- 

 marl while it was in course of formation, the GJohigerince being found 

 crowded round the included lumps. This band is especially notice- 

 able from the fact that the foraminifera present in it are chiefly or 

 almost entirely Glohigerince, although at times a few scattered forms 

 belonging to Ehrenherghia^ Bigenerina, Miliolina, Nodosaria^ and 

 Textularia are found, while in a very few cases Ampliistegina appears. 



This is succeeded by a series of yellowish to bright buff-coloured 

 marls, which frequently have a coarsely granular appearance, due 

 to the presence in great numbers of large, thick-tested Glohigerince, 

 a texture very different from that of the chalks of the Oceanic 

 Series. The lower beds are particularly rich in Glohigerince, 

 and contain few inclusions of the rocks from the Oceanic or the 

 Scotland Beds. Ascending in the series, it is found that the 

 numbers of foraminifera other than Glohigerina rapidly increase, 

 and specimens of Ehrenhergina, Noclosaria, Textidai^ia, Miliolina, 

 Bigenerina, Cristellaria, together with some other forms, become 

 common. The higher beds consist of marls with many Glohigerince 

 and of compact Glohigerina-lim.estoB.es, both containing many 

 inclusions of Oceanic chalks. In the uppermost of these beds, the 

 Glohigerince gradually die out, while other foraminifera (especially 

 Amphisiegina) increase in abundance, and fragments of lamelli- 

 branch shells are commonly present. 



Spines and plates of echinoderms are generally present in all the 

 beds, with the exception of those marls whicli have few inclusions, 

 where they rarely are found. The distribution of echinid debris 

 is very irregular ; in places they are present in great abundance, 

 while in others on the same horizon they may be scarce or apparently 

 totally absent. In some of the blocks of limestone, casts of turbinate 

 corals occur, and at times small joints of Peutacrinus are found. 

 Here and there, through the beds, great numbers of sharks' 

 teeth belonging to Carcharodon, Hemipristis, Ox-yrhina, and Larana 

 are found. In the upper beds many nullipores, notably Litho- 

 thamnium, and millepores occur. 



As the Glohigerince gradually disappear from the upper members 

 of the group, Amjpliisteginoe become common, and in places the 



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