The central part of the skeleton, exhibiting the central junction of the radial spines. Fig. 6. _Acanthometron dolichoscion_, n. sp., × 300 743 Central capsule of a young specimen; in its upper half the peculiar kidney-shaped nucleus is visible, with its invagination; in the lower half some nucleated yellow cells are visible (intracapsular xanthellæ). These and the nucleus are stained by carmine. Fig. 7. _Acanthometron dolichoscion_, n. sp., × 300 743 Cleavage of an isolated nucleus, with four buds. Fig. 8. _Acanthometron dolichoscion_, n. sp., × 300 743 A central capsule with four large budding nuclei; and numerous small spherical nuclei produced by gemmation. Fig. 9. _Acanthonia tetracopa_, n. sp., × 400 749 Central capsule of s young specimen, with a large, irregularly lobate nucleus. Fig. 10. _Acanthonia tetracopa_, n. sp., × 400 749 An isolated nucleus, exhibiting the peculiar invagination, with its circular folds, and the connection with the flatly conical nucleolus. Fig. 11. _Acanthonia tetracopa_, n. sp., × 800 749 Four flagellate spores. [Illustration: 1. ACTINELIUS, 2. LITHOLOPHUS, 3. CHIASTOLUS, 4.-11. ACANTHONIA.] PLATE 130. LEGION ACANTHARIA. Order ACANTHONIDA. Family ASTROLONCHIDA. Fig. 1. _Acanthometron bulbiferum_, n. sp., × 300 745 Fig. 2. _Acanthometron cylindricum_, n. sp., × 200 743 Fig. 3. _Lithophyllium gladiatum_, n. sp., × 200 754 Fig. 4. _Stauracantha quadrifurca_, n. sp., × 300 764 Fig. 5. _Stauracantha orthostaura_, n. sp., × 200 762 Fig. 6. _Phatnacantha icosaspis_, n. sp., × 400 765 Fig. 7. _Pristacantha polyodon_, n. sp., × 300 766 Fig. 8. _Pristacantha dodecodon_, n. sp., × 300 766 Only the central parts and the leaf-cross. Fig. 9. _Pristacantha octodon_, n. sp., × 200 765 [Illustration: 1. 2. ACANTHOMETRON. 3. LITHOPHYLLIUM. 4.-6. STAURACANTHA. 7.-9. PRISTACANTHA.] PLATE 131. LEGION ACANTHARIA. Order ACANTHONIDA. Family QUADRILONCHIDA. Fig. 1. _Quadrilonche mesostaura_, n. sp., × 300 777 Fig. 2. _Quadrilonche platystaura_, n. sp., × 100 777 Fig. 3. _Xiphoptera dodecactena_, n. sp., × 200 778 The central capsule with the central part of the skeleton. Fig. 4. _Lonchostaurus bifurcus_, n. sp., × 300 773 Fig. 5. _Lonchostaurus crystallinus_, n. sp., × 400 773 Fig. 6. _Lonchostaurus rhomboides_, n. sp., × 200 772