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Hystrichosphaeridium perforatum
Hystrichosphaeridium perforatum Gocht, 1959
Now Oligosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Oligosphaeridium.
Holotype: Gocht, 1959, pl.3, fig.7
Age: Hauterivian-Barremian
Original diagnosis: Gocht 1959, p. 68-69: Hystrichosphaeridium perforatum
Central body spherical to egg-shaped, with approximately 15 tubiform processes which are broadened upwardly to projecting, saucer-shaped funnels. The walls of the funnels frequently display round openings. The latter occur either on an individual basis or perforate the funnel in a reticulate manner. Funnel-margins are smooth or slightly serrated. Membranes are thin and finely areolated
Additional Remarks: The species can be readily recognized by the large, saucer-, to plate-shaped funnel opening of the processes. The widening of the processes to funnels occurs always abruptly and without transitional stages, whereby the funnel walls form obtuse angles when vieued in a cross-section. The shafts maintair the same thickness in each case and -- even at the basal regions are barely broadened. Especially conspicuous are the round openings, which frequently disperse the funnel walls and show no regular pattern of distribution. Thus, it will have to be checked first of all whether one is dealing here with some form of injuries or with certain decomposition phenomena which probably had been forced by the structure of the membranes to take on specific forms. Both these assumptions proved to be invalid. Injuries must be excluded right from the beginning, since the openings were always round and displayed smooth margins and since, furthermore, the funnel extremities always displayed entire margins (apart from a few occasional tears, which can be readily recognized as such). In my opinion,decomposition occurrences must likewise be ruled out here. True enough, one might suspect that decomposition phenomena may have played a part here, since the funnels are literally riddled with fine holes just like a fine sieve. However, in case of other funnels, which possess large and more regular perforations, a distinct tendency exists to form interwoven reticulations. Moreover, no signs of decomposition can be discerned along the shafts and along the main body, actually the membranes appear fresh and unattacked. There is no question, however, that the structure of the membrane is partially responsible for the shape of the perforations. Within various objects, number and size of the perforations vary. In two of the three specimens which were at my disposal, these perforations become quite large, and in part, only thin webs separate them then from one another. when viewed from the top, the funnels have a round shape, in one specimen the funnels were triangular , or tetragonal. (Plate 7, Figure 14). The margins are smooth or show angular projections. The tendency of the funnel extremities to show perforations to interwoven reticulations is again apparent in the H. Pulcherrimum DEFL. & COOKSON, which probably is to be derived from the H. complex Greatly perforated funnels of the H. Perforatum partially resemble those of the H. anthophorum COOKS. & EISENACK (1958; in this just mentioned paper, compare Text-Figures 16-18 with Figures 15 and 16 in Plate 7 of the present paper).
Dimensions: Type: Main body 61:56 microns, processes 29-40 microns total diameter 125 microns. The greatest expansion of the remaining specimens amounts to 80 and 100 microns. A rather large, elongated object (Plate 4, Figure 2) resembles our form, hwever, it is in a poor state of preservation, so that the perforations of the turned-
over funnels can not be recognized with 100% certainty (total diameter of this object amounts to 138 microns).
Now Oligosphaeridium. Originally Hystrichosphaeridium, subsequently (and now) Oligosphaeridium.
Holotype: Gocht, 1959, pl.3, fig.7
Age: Hauterivian-Barremian
Original diagnosis: Gocht 1959, p. 68-69: Hystrichosphaeridium perforatum
Central body spherical to egg-shaped, with approximately 15 tubiform processes which are broadened upwardly to projecting, saucer-shaped funnels. The walls of the funnels frequently display round openings. The latter occur either on an individual basis or perforate the funnel in a reticulate manner. Funnel-margins are smooth or slightly serrated. Membranes are thin and finely areolated
Additional Remarks: The species can be readily recognized by the large, saucer-, to plate-shaped funnel opening of the processes. The widening of the processes to funnels occurs always abruptly and without transitional stages, whereby the funnel walls form obtuse angles when vieued in a cross-section. The shafts maintair the same thickness in each case and -- even at the basal regions are barely broadened. Especially conspicuous are the round openings, which frequently disperse the funnel walls and show no regular pattern of distribution. Thus, it will have to be checked first of all whether one is dealing here with some form of injuries or with certain decomposition phenomena which probably had been forced by the structure of the membranes to take on specific forms. Both these assumptions proved to be invalid. Injuries must be excluded right from the beginning, since the openings were always round and displayed smooth margins and since, furthermore, the funnel extremities always displayed entire margins (apart from a few occasional tears, which can be readily recognized as such). In my opinion,decomposition occurrences must likewise be ruled out here. True enough, one might suspect that decomposition phenomena may have played a part here, since the funnels are literally riddled with fine holes just like a fine sieve. However, in case of other funnels, which possess large and more regular perforations, a distinct tendency exists to form interwoven reticulations. Moreover, no signs of decomposition can be discerned along the shafts and along the main body, actually the membranes appear fresh and unattacked. There is no question, however, that the structure of the membrane is partially responsible for the shape of the perforations. Within various objects, number and size of the perforations vary. In two of the three specimens which were at my disposal, these perforations become quite large, and in part, only thin webs separate them then from one another. when viewed from the top, the funnels have a round shape, in one specimen the funnels were triangular , or tetragonal. (Plate 7, Figure 14). The margins are smooth or show angular projections. The tendency of the funnel extremities to show perforations to interwoven reticulations is again apparent in the H. Pulcherrimum DEFL. & COOKSON, which probably is to be derived from the H. complex Greatly perforated funnels of the H. Perforatum partially resemble those of the H. anthophorum COOKS. & EISENACK (1958; in this just mentioned paper, compare Text-Figures 16-18 with Figures 15 and 16 in Plate 7 of the present paper).
Dimensions: Type: Main body 61:56 microns, processes 29-40 microns total diameter 125 microns. The greatest expansion of the remaining specimens amounts to 80 and 100 microns. A rather large, elongated object (Plate 4, Figure 2) resembles our form, hwever, it is in a poor state of preservation, so that the perforations of the turned-
over funnels can not be recognized with 100% certainty (total diameter of this object amounts to 138 microns).