Acanthodesmia vinculata, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 30, Taf. i. figs. 4-6 (non 7).
Lithocircus vinculatus, J. Müller, 1856, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 484.
Frontal ring violin-shaped, one and a half times as broad as high, with a sagittal constriction. Sagittal ring ovate, smaller. The four gates between the two rings are partly fenestrated by a few thin threads, irregularly branched and connecting the two rings. A few short thorns are scattered here and there. Basal gate elliptical.
Dimensions.—Height of the frontal ring 0.12, breadth 0.18.
Habitat.—Mediterranean (Nice), Atlantic (Canary Islands), surface.
2. Acanthodesmia ceratospyris, n. sp.
Frontal ring violin-shaped, one and a half times as broad as high, with a deep sagittal constriction. Sagittal ring semicircular, half as high as the frontal ring. The four gates between the two rings are partly fenestrated by anastomosing branches of the numerous, irregularly branched spines, which cover all three rings. Basal gate nearly circular, smaller than the sagittal ring.
Dimensions.—Height of the frontal ring 0.08, breadth 0.12.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
3. Acanthodesmia corona, n. sp. (Pl. [93], fig. 5).