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Hystrichosphaeridium cribrotubiferum
Hystrichosphaeridium cribrotubiferum Sarjeant, 1960; Emendations: Davey et al., 1966, p.161 and Stancliffe and Sarjeant, 1990, p.207, both as Surculosphaeridium cribrotubiferum.
Now Surculosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Surculosphaeridium.
Holotype: Sarjeant, 1960, pl.6, fig.2, text-fig.1; Stancliffe and Sarjeant, 1990, text-fig.3, nos.4,6
Locus typicus: Furzy Cliff, Weymouth, Oxford Clay
Stratum typicum: Cordatum Zone, Early Oxfordian
Original diagnosis: Sarjeant, 1960, p. 137
A species of Hystrichosphaeridium having a spheroidal shell bearing a moderate number (less than forty) of tubular appendages of variable thickness, arising from broadened bases. The bases sometimes have root-like extensions. The open ends of the appendages give rise to fibrils of very variable length, number and direction: these fibrils sometimes bifurcate. The walls of the tubes are perforate, the perforations being of very constant diameter and distance apart in any particular tube and arranged in rows along the tube"s length. Adjacent perforations in different rows show an arrangement in quincunx in relation to one another.
Original description: Sarjeant, 1960, p. 137
The shell is yellowish in colour and devoid of surface ornament. All specimens seen were in some degree obscured by extraneous organic material caught up by their processes. Dimensions. Type: overall diameter 75 Ám, shell diameter 46 Ám,
processes c. 16 Ám long and 1.5 to 3.5 Ám broad. The range of overall diameters observed was from 60 to 80 Ám.
Affinities:
Sarjeant, 1960, p. 138: The possession of perforations in the tubes, a feature observable only at higher magnification, distinguishes them from all known species of Hystrichosphaeridium. Of existing species, the most closely comparable, is H. salpingophorum (Deflandre) also present at this horizon: this latter spccies also differs in that fibrils at the tube mouth extend as raised striations down the walls of the tube and out onto the tube surface as rootlets, whereas the tubes of H. cribrotubiferum Iack striations.
Now Surculosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Surculosphaeridium.
Holotype: Sarjeant, 1960, pl.6, fig.2, text-fig.1; Stancliffe and Sarjeant, 1990, text-fig.3, nos.4,6
Locus typicus: Furzy Cliff, Weymouth, Oxford Clay
Stratum typicum: Cordatum Zone, Early Oxfordian
Original diagnosis: Sarjeant, 1960, p. 137
A species of Hystrichosphaeridium having a spheroidal shell bearing a moderate number (less than forty) of tubular appendages of variable thickness, arising from broadened bases. The bases sometimes have root-like extensions. The open ends of the appendages give rise to fibrils of very variable length, number and direction: these fibrils sometimes bifurcate. The walls of the tubes are perforate, the perforations being of very constant diameter and distance apart in any particular tube and arranged in rows along the tube"s length. Adjacent perforations in different rows show an arrangement in quincunx in relation to one another.
Original description: Sarjeant, 1960, p. 137
The shell is yellowish in colour and devoid of surface ornament. All specimens seen were in some degree obscured by extraneous organic material caught up by their processes. Dimensions. Type: overall diameter 75 Ám, shell diameter 46 Ám,
processes c. 16 Ám long and 1.5 to 3.5 Ám broad. The range of overall diameters observed was from 60 to 80 Ám.
Affinities:
Sarjeant, 1960, p. 138: The possession of perforations in the tubes, a feature observable only at higher magnification, distinguishes them from all known species of Hystrichosphaeridium. Of existing species, the most closely comparable, is H. salpingophorum (Deflandre) also present at this horizon: this latter spccies also differs in that fibrils at the tube mouth extend as raised striations down the walls of the tube and out onto the tube surface as rootlets, whereas the tubes of H. cribrotubiferum Iack striations.