Description - Add description
Cephalis semispherical, thorax pyramidal.
The basal spines extend from the central rod (under the neck stricture) to the thorax and continue in the thoracic wall to the very margin below where they protrude as “basal feet". The apical spine, D, runs chiefly in the wall of the cephalis (as in the two preceding species) and above is prolongated to a tophorn, which is only very little different to the byspines in appearance. This is also the case with the ventral, sagittal spine, which runs obliquely upwards and out through the neck stricture.
All the main spines are narrow, not three edged.
Cephalis and thorax rather plentifully provided with narrow, needle shaped byspines, which are longest and most numerous on the cephalis. The longest are as long, or even a little longer, than the diameter of the cephalis.
The pores are uneven in shape and size, varying from quite small to 9 µm, not much smaller on the cephalis than on the thorax. Here too the three swellings on the upper part of the thorax between the main spines (fig. 89 b) are to be found.
The width of the lattice shell is 85 µ, its height (not including the basal feet) 68 µm. The cephalis alone is 34 µm wide and 22 µm high.
Very rare and only singly: 19/1 1899, 40 miles NW of Gaukværø, 0 700 m.; Henningsvær, 21/2 1899, 0 250 m.
Distribution: Probably boreal oceanic.
|From Benson, 1966, p. 462 under Remarks; pl. 31, fig. 6, (not figs. 4-5. 7-8):|
Dictyophimus histricosus(?) Jørgensen
A few specimens tentatively identified as Helotholus histricosa Jørgensen have dorsal and primary lateral ribs in the thoracic wall. These extend as terminal feet or foot-like spines (Pl. 31, fig. 6). They more or less conform to Jørgensen's illustration of Dictyophimus histricosus Jørgensen (1905, Pl. 16, fig. 89). However, they may be variant forms of D. gracilipes Bailey from the Gulf. Study of Jørgensen's type material should settle the question whether or not D. histricosus is synonymous with Helotholus histricosa.