N35

Dictyophimus hirundo (Haeckel) group

Pterocorys hirundo Haeckel, 1887, p. 1318, pl. 71, fig. 4; Riedel, 1958, p. 238, pl. 3, fig. 11, pl. 4, fig. 1, text-fig. 9

?Pterocorys (?) hirundo Haeckel, Petrushevskaya, 1967, p. 115, fig. 67, I-III (partim.)

Dictyophimus sp. aff. D. hirundo (Haeckel), Petrushevskaya and Kozlova, 1972, p. 553, pl. 27, figs. 16, 17

Dictyophimus hirundo (Haeckel) group, Petrushevskaya, 1975, p. 583 (partim.)

DESCRIPTION "Cephalis subglobular, with smooth or slightly spiny surface, and numerous small pores which in some specimens are secondarily closed by siliceous lamellae. Apical horn thin, acute, vertical, eccentrically situated, usually approximately as long as the cephalis. In some specimens the "vertical spine" element of the primary spicular skeleton extends beyond the cephalis surface as a second, oblique cephalic horn. Thorax truncate-conical to campanulate, with rather large subcircular or circular pores, its surface usually bearing short, thorn-like spines. Abdomen short, narrower than widest part of the thorax, in many specimens rudimentary or consisting of only one or two rows of subcircular pores separated by narrow intervening bars, with no distinct peristome. In the wall of the thorax are three ribs, continuous with the three three-bladed, acute, divergent, straight or slightly curved feet which arise subterminally from the thorax. At the collar stricture are two pairs of large collar pores separated by the primary lateral spines (L,L), and it is often possible to distinguish also a pair of smaller pores, enclosed by the dorsal (D) and the secondary lateral (l,l) spines in front of the origin of the apical spine." (from Riedel, 1958).

DIMENSIONS "Length of apical horn 7-36 microns, of cephalis 16-27 microns, of thorax 30-70 microns, of feet 35-125 microns. Breadth of thorax 50-90 microns." (from Riedel, 1958).

REMARKS

1. The present authors are doubtful that the specimens from Petrushevskaya and Kozlova (1972), illustrated on Pl. 22, figs. 3a, b herein, belong to the D. hirundo group.

Plate 22, figures 2, 3a,b, 4

N36

RECENT DISTRIBUTION

1. Riedel, 1958; "This species occurs in both the American and Indian Ocean sectors of Antarctic waters, in the tropical parts of the Pacific and Indian Oceans, and in the northern Pacific. It may thus be cosmopolitan."