Fig. 1_a_. Half of the central capsule of another specimen, in which the original central nucleus is cleft into numerous small nuclei, × 400 Fig. 1_b_. Half of the central capsule of another specimen, filled up by flagellate spores, × 400 Fig. 1_c_. Eight isolated flagellate spores, × 800 Fig. 2. _Thalassolampe maxima_, n. sp., × 8 17 The entire living Spumellarium. _c_, The big spherical central capsule; _a_, the large alveoles filling the central capsule and surrounding a central nucleus; _f_, the pseudopodia piercing the extracapsular calymma. Fig. 2_a_. The nucleus alone, with numerous nucleoli, × 30 Fig. 3. _Thalassopila cladococcus_, n. sp., × 20 17 _c_, The big central capsule; _a_, numerous large alveoles contained in the central capsule; _k_, oil globules, many of which are placed in the radially striped cortical zone; the nucleus placed centrally, is covered with numerous radial apophyses or cæcal sacs. _f_, The radially striped calymma. Fig. 4. _Thalassicolla maculata_, n. sp., × 100 21 _c_, The central capsule; _v_, vacuoles filling this capsule; _n_, the central nucleus; _l_, the concentric nucleolus; _g_, the voluminous calymma, a small radial piece of which is only represented; _a_, the large alveoles; _b_, peculiar exoplasmatic bodies; _p_, black pigment in the inner zone; _f_, the retracted pseudopodia in the outer zone. Fig. 4_a_. An exoplasmatic body, × 300 Fig. 4_b_, Vacuoles in the endoplasm, × 300 Fig. 5. _Thalassicolla melacapsa_, n. sp., × 300 21 _n_, The large nucleus; _l_, numerous small nucleoli inside the nucleus; _v_, the vacuoles filling up the central capsule and separated by black pigment; _a_, large alveoles in the calymma; _k_, oil globules; _b_, exoplasmatic bodies; _f_, the retracted pseudopodia in the outer zone of the calymma. Fig. 5_a_. An endoplasmatic vacuole, resembling a cell, × 600 Fig. 5_b_. A piece of the central capsule, × 600 [Illustration: 1. ACTISSA. 2. THALASSOLAMPE. 3. THALASSOPILA. 4. 5. THALASSOCOLLA.] PLATE 2. LEGION SPUMELLARIA. Order BELOIDEA. Family THALASSOSPHÆRIDA. Fig. 1. _Lampoxanthium pandora_, n. sp., × 120 38 The central capsule exhibits distinct pore-canals in its membrane, and a clear interval between this and the coagulated and vacuolated protoplasm. The central nucleus contains numerous dark nucleoli. The spicula are scattered throughout the alveolate calymma.