S19

Polysolenia spinosa (Haeckel)

Collosphaera spinosa Haeckel, 1860b, p. 845; 1862, p. 536, pl. 34, figs. 12, 13

Polysolenia spinosa (Haeckel), Nigrini, 1967, p. 14, pl. 1, fig. 1

DESCRIPTION "Shell thin-walled, smooth, spherical, with numerous, irregularly scattered, subcircular pores of variable size, 1-4 times as broad as the bars. Short spines, usually mounted on conical elevations, project randomly over the shell surface, either singly from pore margins or from between the pores. Spines are usually conical, but may be quite sharp; often they are fenestrate near the shell and sometimes arise from as cluster of small pores rather than from a single pore. Probably these pore clusters form when a single pore is divided by a growing spine." (from Nigrini, 1967).

DIMENSIONS "Diameter of shell 81-164 microns (usually 81-128 microns)." (from Nigrini, 1967).

REMARKS

1. For a more complete synonymy see Nigrini, 1967.

Plate 2, figure 5

S20

RECENT DISTRIBUTION

1. Nigrini, 1967, fig. 2; " Indian Ocean occurrences - P. spinosa is sparsely distributed in both low and middle latitudes. It forms a high percentage (17%) of the described population in a sample near the African coast (SERPENT(?) 9); and in two samples near the southern limit of tropical radiolarian distribution (VEMA 18-201, 21 degrees 02 minutes S; and LSDA 119G, 22 degrees 02 minutes S) the species constitutes 12 percent and 10 percent respectively of the described population."

2. Molina-Cruz, 1975, Code S13; used in factor analysis of southeast Pacific assemblages; cf. Appendix 10 for percent S13 at each station.

3. Morley, 1977; Fig. I-4; " This species loads highest in factor 4 (subtropical). At present its maximum abundance is centered in the middle of the Subtropical Gyre. Although no samples at the 18,000 year level contained Radiolaria from the region where this species is most abundant, the similarity in percentages in peripheral areas would indicate that at 18,000 YBP there may have not been much variation in the abundance of this species."