. Bulletin of the British Museum (Natural History) Geology Supplement. MESOZOIC AND CAINOZOIC DINOFLAGELLATE CYSTS 81 Range of British Cenomanian forms : diameter of central body 21-47(1 (mean 34.(1), length of processes 4—25( Number of specimens measured, 160. Description. The periphragm of the central body at first sight appears to be granular, but at high magnification is seen to be reticulate. The processes, though normally cylindrical or subcorneal, can be mammiform or even saucer-shaped (Text-fig. 17), the latter being 4~5(x in height. Very occasionally closed processes are present be
. Bulletin of the British Museum (Natural History) Geology Supplement. MESOZOIC AND CAINOZOIC DINOFLAGELLATE CYSTS 81 Range of British Cenomanian forms : diameter of central body 21-47(1 (mean 34.(1), length of processes 4—25( Number of specimens measured, 160. Description. The periphragm of the central body at first sight appears to be granular, but at high magnification is seen to be reticulate. The processes, though normally cylindrical or subcorneal, can be mammiform or even saucer-shaped (Text-fig. 17), the latter being 4~5(x in height. Very occasionally closed processes are present being either apical processes or small sulcal processes. L. siphoniphorum has been recorded from the Albian of Australia and Roumania, and the Cenomanian of Australia and Britain. Remarks. The British Cenomanian specimens from Surrey agree fairly closely with the examples from Australia. The Surrey specimens appear to be smaller, but unfortunately the range of the Australian forms was not given in the description so no true size comparison can be Fig. 17. Litosphaeridium siphoniphorum (Cookson & Eisenack). A figure illustrating the variation in the size and shape of the processes (based on specimens from the Ceno- manian) .. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). London : BM(NH)
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