5. Castanarium huxleyi, n. sp.
Pores irregularly polygonal, two to three times as broad as the bars, separated by prominent polygonal crests. Radial bristles half as long as the radius.
Dimensions.—Diameter of the shell 0.45, of the pores 0.02 to 0.05.
Habitat.—South Pacific (off Australia), Station 165, surface.
Genus 706. Castanella,[[323]] Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 5.
Definition.—Castanellida without radial main-spines, with a dentate mouth.
The genus Castanella comprises the most common and most widely distributed species of Castanellida. It agrees in general shape with its ancestral form, the preceding Castanarium, differing from it only in the possession of strong teeth, which form a corona around the mouth.
1. Castanella wyvillei, n. sp. (Pl. [113], fig. 6).
Pores regular, circular, of equal size, hexagonally framed, of the same breadth as the bars. Radial bristles twice as long as the diameter of one pore. Mouth with five to six parallel, conical strong teeth, which are twice as long as a bristle (fig. 6a).
Dimensions.—Diameter of the shell 0.5 to 0.7, of the pores 0.02 to 0.03.