Page:Scientific results HMS Challenger vol 18 part 1.djvu/1028

820 apertures; twenty larger dimples in the centre of the plates (each with a couple of aspinal pores) and fifty to one hundred or more smaller dimples, each of which contains one sutural pore. No blind dimples between the perforated dimples.

1. Ceriaspis lacunosa, n. sp.

Shell spherical with seventy-two funnel-shaped dimples, each of which is perforated on the bottom by one or two apertures; twenty larger dimples in the centre of the plates, each with two elliptical aspinal pores, and fifty-two smaller sutural dimples between them, each with one circular pore of half the size. No blind dimples. Radial spines quadrangular, stout; their outer part shorter than the inner.

Dimensions.—Diameter of the shell 0.1, of the forty parmal pores 0.01, of the fifty-two sutural pores 0.005.

Habitat.—South Atlantic, Station 330, surface.

2. Ceriaspis scrobiculata, n. sp.

Shell spherical, with seventy-four funnel-shaped dimples, each of which is perforated on the bottom by one or two apertures; twenty larger dimples in the centre of the plates, each with two kidney-shaped large pores, and fifty-four smaller dimples on the sutures, each with one circular pore of one-fourth of the size of the reniform pores. No blind dimples. Radial spines cylindrical, the outer part longer than the inner.

Dimensions.—Diameter of the shell 0.12, of the forty parmal pores 0.016, of the fifty-four sutural pores 0.004.

Habitat.—Central Pacific, Station 270, surface.

Definition.—Shell-surface with funnel-shaped dimples (commonly one hundred and seventy-six or one hundred and eighty-two), which on the bottom are partly closed, partly perforated by one aperture (or by a pair of pores). The blind dimples are placed on the corners of the twenty plates, and are therefore either one hundred and four or one hundred and eight; if there be no polar suture, the blind dimples are one hundred and four (twenty-four on the four hexagonal equatorial plates, forty on the eight pentagonal tropical plates, and forty on the eight pentagonal polar plates); if, however, there be a polar suture on both main poles, the number of blind dimples is one hundred and eight (twenty-four on the four hexagonal equatorial and twenty-four on the four hexagonal polar plates, two opposite on each pole; forty on the eight pentagonal tropical plates and twenty on the four pentagonal polar plates, two opposite on each pole). Between the blind dimples there are usually seventy-two to seventy-four perforated