Subgenus 2. _Toxidium_, Haeckel. _Definition._--Galear bows simple, thoracal bows forked. 5. _Toxarium cordatum_, n. sp. (Pl. 93, fig. 19). Galear bows simple, thoracal bows forked, both somewhat smaller than frontal bows; all bows armed with scattered simple conical spines, mostly developed at the thoracal bows. Both galear bows are united in a central vertical columella, which arises from the apex of the sagittal ring, and is prolonged into an apical horn. Therefore the sagittal constriction exists only in the basal half of the inversely cordate shell. _Dimensions._--Length of the shell 0.18, breadth 0.16. _Habitat._--South Atlantic, Station 348, depth 2450 fathoms. {997}6. _Toxarium furcatum_, n. sp. Galear bows simple, thoracal bows forked, both somewhat broader than the frontal bows. Shell therefore slightly constricted in the equatorial plane. Sagittal constriction rather deep, equal in the apical and basal parts. All bows armed with scattered spines, which are partly simple, partly forked. _Dimensions._--Length of the shell 0.14, breadth 0.16. _Habitat._--Central Pacific, Station 270, depth 2925 fathoms. 7. _Toxarium pedatum_, n. sp. Galear bows simple, smaller than the frontal bows, which are again smaller than the thoracal bows. Therefore the breadth of the shell increases towards the base. Sagittal constriction flat in the apical part, deep in the basal part. All bows armed with small irregularly scattered spines; at the base six larger divergent feet (two lateral, two anterior, and two posterior). _Dimensions._--Length of the shell 0.17, breadth 0.15. _Habitat._--South Pacific, Station 295, depth 1500 fathoms. Subgenus 3. _Toxonium_, Haeckel. _Definition._--Galear and thoracal bows forked. 8. _Toxarium costatum_, n. sp. Galear and thoracal bows forked, smaller than the frontal bows, all bows thorny, without larger spines. Sagittal constriction on both poles deep. Lateral outlines of the shell nearly parallel. _Dimensions._--Length of the shell 0.15, breadth 0.12. _Habitat._--Indian Ocean, Socotra (Haeckel), surface. 9. _Toxarium bifurcum_, n. sp. (Pl. 93, fig. 20). Galear and thoracal bows forked, the former smaller than the frontal bows, the latter larger. Sagittal constriction rather flat on the apical pole, which bears a vertical forked horn, very deep on the basal pole of the primary ring. All bows armed with numerous spines, which are partly simple, partly forked, and mainly developed at the basal part of the thoracal bows. _Dimensions._--Length of the shell 0.2, breadth 0.2. _Habitat._--Central Pacific, Station 271, depth 2425 fathoms. Genus 428. _Microcubus_,[47] Haeckel, 1881, Prodromus, p. 447. _Definition._--#Tympanida# with two bisected horizontal rings, connected by four vertical columellæ, which are bisected again by an equatorial ring.