Parmal meshes irregular, polygonal or roundish, six to eight times as broad as the narrow and high bars, much larger than the irregular sutural meshes. Radial spines leaf-shaped, compressed, two-edged, pointed at both ends; inner and outer part nearly of equal size. Shell very thick walled; meshes therefore funnel-shaped; sutures completely obliterated, therefore the whole shell forms a single piece.
Dimensions.—Diameter of the shell 0.09, parmal pores 0.02, sutural pores 0.01.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
Genus 363. Lychnaspis,[[403]] Haeckel, 1862, Prodromus, p. 468.
Definition.—Dorataspida with twenty plates, which are perforated by eighty aspinal pores (four crossed pores in each plate). Surface covered with numerous by-spines.
The genus Lychnaspis, the largest and most common of all Dorataspida, exhibits the same structure of the shell as its ancestral form Tessaraspis, and differs from it only in the development of by-spines on the sutural condyles. Many species of this genus are very widely distributed, and appear in large numbers, and some of them are amongst the most graceful and elegant of the Radiolaria.
Subgenus 1. Lychnasparium, Haeckel.
Definition.—Condyles of the neighbouring plates connected by permanent open sutures; therefore the whole shell is composed of twenty separate pieces of acanthin.
1. Lychnaspis giltschii, n. sp. (Pl. [135], fig. 3).
Parmal meshes pentagonal, about ten or twelve times as broad as the thin bars, on an average of the same size as the irregular polygonal sutural meshes. By-spines (two hundred to three hundred) very delicate, half as long as the radius, barbed, and zigzag. Radial main-spines very thin and long, straight, cylindrical; their outer part longer than the inner part.