7. Lithoptera darwinii, Haeckel.
All twenty spines with transverse apophyses; these are quite simple in the eight small cross-shaped polar spines; also simple, but bearing some perpendicular rods, in the eight thin tropical spines. Four equatorial spines very large and stout, each crossed by four transverse beams, which are connected by eight to ten rods parallel to the spine (therefore each wing with three rows of irregular rectangular meshes). Wings placed in the equatorial plane and grown partly together by their meeting lateral ends.
Dimensions.—Diagonal of the square body 0.4; length of the inner square 0.2.
Habitat.—South-east Pacific, west coast of Patagonia, Station 302, surface.
8. Lithoptera icosaptera, n. sp.
All twenty spines with transverse apophyses, bearing one to three rows of rectangular meshes; eight polar spines small, each with a single row; eight tropical spines long and thin, each with two parallel rows. Four equatorial spines much larger and thicker, each with three parallel transverse rows of meshes. All twenty wings free, not grown together by their lateral ends.
Dimensions.—Diagonal of the square body 0.48; length of the inner square 0.24.
Habitat.—Indian Ocean, Belligemma, Ceylon (Haeckel), surface.
9. Lithoptera fenestrata, J. Müller.
All twenty spines with transverse apophyses, bearing one to three rows of irregular, rectangular meshes; eight polar and eight tropical spines small, each with a single row of meshes (between two parallel transverse beams). Four equatorial spines little larger, each with two rows (between three parallel transverse beams). Central capsule filled up with green pigment.
Dimensions.—Diagonal of the square body 0.3; length of the inner square 0.2.
Habitat.—Mediterranean (Saint Tropez, Nice).
Family XXXVIII. Amphilonchida, Haeckel (Pl. 132).
Acantholonchida (Amphilonchida et Amphilithida), Haeckel, 1881, Prodromus, p. 466.
Definition.—Acantharia with twenty radial spines of very unequal size, disposed according to the law of the Icosacantha; two opposite equatorial spines (in the longitudinal axis) much larger than the eighteen others. No lattice-shell.
The family Amphilonchida is distinguished from all other Acanthometra by the excessive development of two opposite equatorial spines, which are much larger
