11. Amphilonche complanata, Haeckel.

Amphilonche complanata, Haeckel, 1862, Monogr. d. Radiol., p. 390, Taf. xvi. fig. 3, Taf. xviii. fig. 18, a, b.

Acanthometra complanata, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 808.

Two principal spines compressed, two-edged, linear, of equal breadth throughout their whole length; apex emarginate or bifid; base with a large leaf-cross of double the breadth. Eighteen smaller spines of the same form, but only one-fourth to one-half as large. Central capsule ellipsoidal, yellow, pellucid.

Dimensions.—Length of the two major spines 0.15 to 0.25, breadth 0.004 to 0.006; length of the eighteen minor spines 0.05 to 0.1.

Habitat.—Mediterranean (Messina), surface.

12. Amphilonche messanensis, Haeckel.

Amphilonche messanensis, Haeckel, 1862, Monogr. d. Radiol., p. 391, Taf. xvi. fig. 4, Taf. xviii. fig. 19.

Acanthometra messanensis, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 808.

Two principal spines quadrangular prismatic, often a little compressed from two sides, of nearly equal breadth throughout their whole length; apex either truncate or emarginate, with two opposite teeth; base with a large leaf-cross of double the breadth. Eighteen smaller spines of similar form or more compressed, much shorter. Central capsule spherical or ellipsoidal, yellow, transparent.