Pores irregular, roundish or polygonal, two to four times as broad as the bars. Bristles about one-fourth as long as the radius. Radial main-spines numerous, straight, conical, stout, with dimpled surface, shorter than the radius. Mouth with six to eight irregular conical teeth.
Dimensions.—Diameter of the shell 0.32, of the pores 0.012 to 0.024.
Habitat.—Tropical Pacific, Station 268, depth 2900 fathoms.
6. Castanissa hoylei, n. sp.
Pores irregular, polygonal, two to three times as broad as the bars. Bristles nearly half as long as the radius. Radial main-spines (about thirty) very long and thin, cylindrical, irregularly curved, at the conical base inflated and fenestrated; shell therefore slightly polyhedral. Mouth with five strong conical teeth.
Dimensions.—Diameter of the shell 0.35 to 0.4, of the pores 0.02 to 0.03.
Habitat.—North Pacific, Station 245 to 250, surface.
Genus 709. Castanopsis,[[326]] Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 5.
Definition.—Castanellida with branched radial main-spines and a simple smooth mouth.
The genus Castanopsis differs from its ancestral form Castanidium in the ramification of the radial main-spines; the branches are usually very irregular and often partly confluent. The shell is very similar to the Astrosphæride Cladococcus (compare above p. [223], Pl. [27]), but differs from it in the possession of the shell-mouth, absent in all Sphæroidea.