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Cenosphaera cristata sensu Riedel, 1958

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Cenosphaera cristata Haeckel ?
Spherical shell thick-walled, thorny. Pores subcircular or circular, variable in size, 10-24 on the half-equator, as wide to five times as wide as the intervening bars. Pores surrounded by raised polygonal frames bearing short thorns at the corners—in rare specimens the polygonal frames are absent but the thorns present. Diameter of shell 115-230 µ.
Measurements based on 5 specimens from Sta. 30, 25 from Sta. 94, and one each from Stas. 97 and 103.
This form can be identified only doubtfully with Haeckel's species, because of the brevity of the original description and lack of an illustration. The question can be settled only by re-examination of specimens from the type locality, namely the North Pacific " Challenger " Sta. 254. The Antarctic specimens show greater variability than is indicated in Haeckel's description. The Antarctic species resembles to some extent Cenosphaera favosa Haeckel (1887, 62, PI. 12, fig. 10) and C. globosa Popofsky (1908, 207, PI. 22, fig. 2), from both of which if differs in the irregularity of the pores. Rather similar thorny, thick-walled species of this genus have been recorded from the Antarctic by Haeckel (1887, 65 ; C. solida) and Popofsky (1908, 207 ; C. globosa and C. solida). However, a large number of species of Cenosphaera have been described, in many instances inadequately, from both high and low latitudes, and the pattern of distribution of members of this group cannot be determined until the relationships between the various species are more satisfactorily understood.
sensu Riedel 1958
Cenosphaera cristata(?)
Skeleton single, sphere devoid of radial spicules, very massive. Walls thick, rough; indistinct frame around pores. Pores of nonuniform size, oval or rounded, irregularly disposed. Number of pores varies from 11 to 16 on half equator.
Dimensions: diameter of shell 150-220µ.
Location. Not found in plankton. Found by Riedel in the Antarctic (stations 30, 94, 97, and 103 of BANZARE) . In our material shells encountered in samples of sediments taken from south of zone of Antarctic convergence in Indian and Pacific Ocean sectors (Figure 93,11). In shelf sediments usually absent, and in deepwater sediments shells of this species usually constitute less than 1% of total number and only in places 1—2%. North of zone of Antarctic convergence very similar shells encountered.
Note. This is the same species as that drawn by Riedel as C. cristata(?), but its definition as C. cristata Haeckel is to a large degree conditional. Riedel himself mentions this, noting the brevity of Haeckel' s description and the absence of a drawing. Riedel indicates that the species to some extent resembles C. favosa Hck. , C. solida Hck., and C. globosa Popofsky, but differs from these by the irregular disposition of the pores and from C. globosa by the larger dimensions also. Riedel writes that the lack of detail in the descriptions of these species and the absence of drawings make compari son difficult and that in general the taxonomy of genus Cenosphaera Ehrenberg, 1854 has hardly been elaborated and requires revision. Because the definition of this species is provisional it is difficult to enlarge upon its general distribution. Apart from the shells described above, far smaller shells (diameter 100-130µ) and with fewer pores (10-2 on half equator) are sometimes encountered in the Antarctic sediments. Their walls are coarse, the pores are of unequal diameter and are disposed irregularly (Figure 7, III, IV). Riedel considered these shells to belong to C. cristata(?) from the range of variation of their sizes. They should possibly be regarded as a special variant of this species. We found one such specimen at station 287 in the plankton haul from the 0-200-m layer. These shells are distributed in the sediments like the shells of the typical form.

Petrushevskaya 1967


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