Genus 255. Spongolonche,[[294]] Haeckel, 1881, Prodromus, p. 461.
Definition.—Spongodiscida with two solid marginal spines, opposite in one equatorial diameter of the disk.
The genus Spongolonche opens the series of the Spongotrochida, or of those Spongodiscida in which the margin of the disk is armed with solid radial spines, situated in the equatorial plane. Spongolonche possesses only two such spines, opposite in one equatorial diameter of the disk; it corresponds therefore to Stylocyclia among the Coccodiscida, to Xiphodictya among the Porodiscida.
1. Spongolonche conostyla, n. sp..
Spongy disk circular, with irregular framework, without concentric rings. Both opposite radial spines conical, about as long as the radius of the disk, and four times as long as broad at the base. Margin of the disk nearly smooth.
Dimensions.—Diameter of the disk 0.16; length of the radial spines 0.18, basal thickness 0.045.
Habitat.—Pacific, central area, Station 268, depth 2900 fathoms.
2. Spongolonche amphistyla, n. sp.
Spongy disk circular, with four to six concentric rings in the inner part, with quite an irregular framework in the outer part. Both opposite radial spines cylindrical, twice to three times as long as the diameter of the disk, at the base about as broad as two meshes of the framework. Margin of the disk ciliated.
Dimensions.—Diameter of the disk 0.2; length of the radial spines 0.4 to 0.6, basal thickness 0.01.