Fig. 5. _Sphærozoum variabile_, n. sp., × 300 45 Three isolated spicula. Fig. 6. _Sphærozoum pandora_, n. sp. (vel _Rhaphidozoum pandora_), × 300 49 A group of various spicula. Fig. 7. _Sphærozoum verticillatum_, n. sp., × 300 44 A single spiculum. Fig. 8. _Sphærozoum arborescens_, n. sp., × 300 44 A single spiculum. Fig. 9. _Sphærozoum armatum_, n. sp., × 300 43 A single spiculum. [Illustration: SPHAEROZOUM.] PLATE 5. LEGION SPUMELLARIA. Order SPHÆROIDEA. Family COLLOSPHÆRIDA. Fig. 1. _Trypanosphæra transformata_, n. sp., × 150 111 A living colony. The centre of the spherical coenobium contains a large alveole, surrounded by a net of sarcode. The entire calymma is filled up by smaller, thin-walled alveoles. Its inner part contains numerous small, young, central capsules (each with an oil-globule) without shells; in the cortical zone of the calymma lie larger capsules, each of which is enclosed by a fenestrated shell with from two to four or more dentated tubes. Between the radiant pseudopodia very numerous small yellow cells (xanthellæ), which are scattered everywhere. Fig. 2. _Trypanosphæra transformata_, n. sp., × 300 111 A single shell. Fig. 3. _Trypanosphæra coronata_, n. sp., × 300 110 Fig. 4. _Trypanosphæra trepanata_, n. sp., × 300 110 Fig. 5. _Odontosphæra monodon_, n. sp., × 300 102 Fig. 6. _Odontosphæra cyrtodon_, n. sp., × 300 102 Fig. 7. _Acrosphæra inflata_, n. sp., × 300 101 Fig. 8. _Mazosphæra hippotis_, n. sp., × 400 108 Fig. 9. _Mazosphæra lagotis_, n. sp., × 300 108 Fig. 10. _Pharyngosphæra stomodæa_, n. sp., × 400 98 Fig. 11. _Buccinosphæra invaginata_. n. sp., × 500 99 Each shell contains numerous larger and smaller crystals. Fig. 12. _Tribonosphæra centripetalis_, n. sp., × 500 98 Each shell contains numerous large crystals. Fig. 13. _Collosphæra polygona_, n. sp., × 200 96 [Illustration: 1-4. TRYPANOSPHAERA. 5-9. MAZOSPHAERA. 10. 11. BUCCINOSPHAERA. 12. 13. COLLOSPHAERA.] PLATE 6. LEGION SPUMELLARIA. Order SPHÆROIDEA. Family COLLOSPHÆRIDA. Fig. 1. Siphonosphæra socialis, n. sp., × 500 106