. Bulletin of the Natural Histort Museum. Geology series. Fig. 39 Torreyites detriti sp. nov. From Wessex Formation, Isle of Wight. Inside of lower cuticle showing stomata scattered within longitudinal groove, SEM, Fig. 40 Torreyites detriti sp. nov. From Wessex Formation, Isle of Wight. One stomatal groove showing distribution of stomata and orientation of slit-like stomatal openings, , x 200. that this species was also deciduous. Examples of fossil populations representing mass leaf drops (brachyblasts) have been noted as a widespread phenomenon in Phoenicopsis, Czekano
. Bulletin of the Natural Histort Museum. Geology series. Fig. 39 Torreyites detriti sp. nov. From Wessex Formation, Isle of Wight. Inside of lower cuticle showing stomata scattered within longitudinal groove, SEM, Fig. 40 Torreyites detriti sp. nov. From Wessex Formation, Isle of Wight. One stomatal groove showing distribution of stomata and orientation of slit-like stomatal openings, , x 200. that this species was also deciduous. Examples of fossil populations representing mass leaf drops (brachyblasts) have been noted as a widespread phenomenon in Phoenicopsis, Czekanowskia and Spheuobaiera by Vakhrameev (1991). PseitdotorelUa linkii occurs in a similar type of deposit in Dunker's 'Abietites leaf coal' in the Wealden of Germany, though such concentrations have not been recognized in the English Wealden. Bose & Manum (1990, 1991) have also described needle-leaved conifers of the PseudotoreUial Sciadopityoides-type in pure leaf coals together with Siilcatocladits- type shoots (see discussion above). Clearly, all these occurrences of ginkgoalean, czekanowskialean and coniferalean brachyblasts indi- cate deciduousness, which itself indicates seasonality of some kind. This scenario of mixed gymnospemi forests in moister valleys is not inconsistent with the current consensus view of the climate of the Wealden, as drawn from a wide range of disciplines by Allen (1998). He describes a very warm, seasonal 'Mediterranean' climate with occasional equable humid periods and generally wetter conditions on the upland massifs than in the plains. However, the presence of the species described here suggests that localized upland areas may have remained moist for sustained periods, allowing the development of mixed forest groves. It is hoped that further studies of plant debris material will continue to improve our understanding of Wealden palaeoecology and climate. Acknowledgements. We are most grateful to those who provided us with debris material which
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