N9

Ceratospyris borealis Bailey

The taxonomic position of this species is completely uncertain. Dr. Robert Goll (personal communication) is presently reviewing Recent Spyroids and will, hopefully, provide a basis for the placement of this species through observations of the Spyroids as a group. This species is common in high northern latitudes and has been well illustrated, but poorly described, by a number of workers under a variety of names. Bailey's (1856) description and illustration of Ceratospyris borealis are both poor. However, since he was describing commonly-occurring Recent North Pacific radiolarians, it is not unlikely that he indeed saw the species now under discussion. Therefore, the name Ceratospyris borealis Bailey is used herein with the understanding that it is used purely as a matter of convenience. This species has been variously presented under the following names:

Ceratospyris borealis Bailey, 1856, p. 31, pl. 1, fig. 3; Kruglikova, 1969, fig. 4-15

Tholospyris? sp. Kruglikova, 1969, fig. 4-13

Tristylospyris sp. Nigrini, 1970, p. 170, pl. 3, figs. 3-6

Triceraspyris?sp. Ling et al., p. 713, pl. 2, figs. 1-3

Tholospyris spinosus Kruglikova, 1974, p. 193, pl. 2, figs. 10-11

DESCRIPTION

"The two forms of radiolarian shell with a sagittal ring recovered from the Bering Sea surface sediments are grouped here.

"The first form is similar to Ceratospyris borealis originally proposed by BAILEY (1856, p. 3, pl. 1 fig. 3) and is illustrated by KRUGLIKOVA (1969, fig. 4-15). NIGRINI [1970] discussed it under the name of Tristylopsyris sp.

"The second form has skeletal elements similar to the first, but has more lattice bars on the lattice shell and consequently smaller and more circular, lattice pores; has short projections at the junctions of lattice bars; and has slightly longer and distinct basal spines. Judging from the illustration, KRUGLIKOVA (1969, fig. 4-13) encountered the form and it is illustrated under the name of Tholospyris (?) sp.

"The joint occurrence of these two forms was also noticed by the senior author in his study of eastern and central subarctic surface sediments. An Antarctic species, Triceraspyris antarctica (RIEDEL 1958; PETRUSHEVSKAYA 1964, 1967) also seems closely related to the present forms but it differs by posessing much longer and distinct basal spines, and no such specimens were found during the present study.

"Thus samples from the Antarctic region must be examined before a relationship between the forms of both hemispheres is resolved, or before these two forms found in the Bering Sea should be considered as a separate taxon." (from Ling et al., 1971).

Plate 19, figures 1a-d

N10

Kruglikova (1974) described Tholospyris spinosus n.sp. with the following diagnosis:

"Differs from Tholospyris borealis in having more numerous and smaller pores. The spinosity of the skeleton is well expressed. The skeleton is slightly narrowing toward the basal part. The terminal legs are better developed and frequently porous. The measurements of the skeleton are usually smaller than in T. borealis."

DIMENSIONS

"Width of lattice shell 120-190 microns, height of sagittal ring 90-140 microns" (from Ling et al., 1971).

"Width 135 +\- 16 microns; height, 108 +\- 12 microns; based on 15 specimens" (from Sachs, 1973).

RECENT DISTRIBUTION

1. Nigrini, 1970, fig. 23; belongs to a subarctic assemblage derived by recurrent group analysis of North Pacific samples.

2. Ling et al., 1971, fig. 7; "found frequently in most of the samples" [from the Bering Sea]. Also "noticed... in... eastern and central [Pacific] subarctic surface sediments".

3. Sachs, 1973, Code 26N, fig. 2F; "...an important species (to 25%) in Northern stations, and loads heavily on the Polar Factor".

4. Robertson, 1975; "Two forms of this species are described by Ling and others (1971). However, only the first form described by them is included in the counts for this species in this study. This form is similar to Ceratospyris borealis Bailey and is characterized by its well-exposed sagittal rings, few lattice bars, and open lattice structure.

"This species loads most heavily in factor 1 (subpolar). At both the present and 18,000 YBP some of the more southern samples have higher percentages than at the present."