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Hystrichosphaeridium mantellii
Hystrichosphaeridium mantelli Davey and Williams, 1966
Now Florentinia. Originally Hystrichosphaeridium, subsequently (and now) Florentinia.
Holotype: Davey and Williams, 1966, pl.6, fig.6
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Late Cenomanian
Original diagnosis: Davey and Williams, 1966, p. 66
Spherical to sub-spherical central body composed of thin endophragm and granular or finely reticulate periphragm. Periphragm of processes slightly fibrous. Processes predominantly simple, tubiform, buccinate or bulbose, open distally with digitate or foliate margin. Occasionally narrow, solid, closed processes occur. Number of processes 26 or less, one process per plate area. Apical archaeopyle usually present.
Dimensions: holotype: diameter of central body 41 by 42 µm, length of processes
13-21 µm, number of processes 25. Range: diameter of central body 36-45 µm, length of processes 13-26 µm.
Original description: Davey and Williams, 1966, p. 66
At first sight the periphragm of the central body appears to be fairly heavily granular, but on closer examination the granules apparently result from a fine reticulation. The processes are erect and extremely variable in form, being tubiform, buccinate or even bulbose, usually open but occasionally closed, and simple or branched distally. The closed processes are extremely narrow, less than 1 µm, and solid distally. An apical archaeopyle appears always to be present. The processes give a reflected tabulation of 6"", 6c, 5""", 1p, 1"""" and a variable number of sulcal processes, commonly 4-6. The detached apical region has not yet been identified.
Affinities:
Davey and Williams, 1966, p. 66: The reticulate nature of the central body and the fibrous processes differentiate H. mantelli from most other species. H. radiculatum is, however, fairly similar but the processes are more deeply divided, there often being 2 to 3 sub-parallel branches, and narrower.
Now Florentinia. Originally Hystrichosphaeridium, subsequently (and now) Florentinia.
Holotype: Davey and Williams, 1966, pl.6, fig.6
Locus typicus: Fetcham Mill, Surrey, England
Stratum typicum: Late Cenomanian
Original diagnosis: Davey and Williams, 1966, p. 66
Spherical to sub-spherical central body composed of thin endophragm and granular or finely reticulate periphragm. Periphragm of processes slightly fibrous. Processes predominantly simple, tubiform, buccinate or bulbose, open distally with digitate or foliate margin. Occasionally narrow, solid, closed processes occur. Number of processes 26 or less, one process per plate area. Apical archaeopyle usually present.
Dimensions: holotype: diameter of central body 41 by 42 µm, length of processes
13-21 µm, number of processes 25. Range: diameter of central body 36-45 µm, length of processes 13-26 µm.
Original description: Davey and Williams, 1966, p. 66
At first sight the periphragm of the central body appears to be fairly heavily granular, but on closer examination the granules apparently result from a fine reticulation. The processes are erect and extremely variable in form, being tubiform, buccinate or even bulbose, usually open but occasionally closed, and simple or branched distally. The closed processes are extremely narrow, less than 1 µm, and solid distally. An apical archaeopyle appears always to be present. The processes give a reflected tabulation of 6"", 6c, 5""", 1p, 1"""" and a variable number of sulcal processes, commonly 4-6. The detached apical region has not yet been identified.
Affinities:
Davey and Williams, 1966, p. 66: The reticulate nature of the central body and the fibrous processes differentiate H. mantelli from most other species. H. radiculatum is, however, fairly similar but the processes are more deeply divided, there often being 2 to 3 sub-parallel branches, and narrower.