5. Polyplecta dumetum, Haeckel.
Acanthodesmia dumetum, J. Müller, 1868, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 30, Taf. i. Fig. 3.
Numerous (ten to twelve or more) radial spines, thin and straight, with a few straight lateral branches, diverge in different directions and are connected by a few slender curved arches. Some similar forms, but more developed, with numerous branches and curved rods, are found in the Pacific Radiolarian ooze, and represent probably different species.
Dimensions.—Length of the radial spines 0.05 to 0.08, of the branches 0.02 to 0.03.
Habitat.—Mediterranean, French shore (Cette and Saint Tropez), Johannes Müller, surface.
Suborder III. STEPHOIDEA, Haeckel.
Stephoidea vel Stephida, Haeckel, 1881, Prodromus, p. 444.
Acanthodesmida (sensu ampliori), Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 495.
Definition.—Nassellaria without complete lattice-shell, with a skeleton composed of one or more simple rings, which may be united by a loose framework and are separated by large openings or gates. One primary or sagittal ring, determining the sagittal or median plane of the bilateral body, encloses the monaxonian central capsule.