Cephalis quadrilobate; the odd frontal and the two paired buccal lobes hemispherical, about half as large as the helmet-shaped occipital lobe. Thorax cylindrical, of equal length and breadth, one and a half times as broad as the cephalis and as the cylindrical abdomen. Pores rather large, irregular, roundish. _Dimensions._--Length of the shell 0.12, breadth 0.06. _Habitat._--Central Pacific, Station 274, depth 2750 fathoms. 3. _Botryocyrtis cerebellum_, n. sp. (Pl. 96, fig. 18). Cephalis quinquelobate; the odd frontal and the two paired buccal lobes ovate, about half as large as the two helmet-shaped paired occipital lobes (?). Thorax campanulate, twice as broad and long as the cephalis and as the truncate cylindrical abdomen. _Dimensions._--Length of the shell 0.12, breadth 0.08. _Habitat._--South Atlantic, Station 332, depth 2200 fathoms. 4. _Botryocyrtis quinaria_, Ehrenberg. _Botryocyrtis quinaria_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 16. Cephalis quinquelobate; the odd occipital lobe ovate, twice as large as each of the other four subspherical lobes, the two anterior (or frontal) of which are somewhat smaller than the two posterior (or buccal). Thorax campanulate, somewhat larger than the truncate abdomen. Pores rather large, irregular. _Dimensions._--Length of the shell 0.09, breadth 0.05. _Habitat._--Indian Ocean (Zanzibar and Madagascar), surface. Genus 493. _Pylobotrys_,[110] Haeckel, 1881, Prodromus, p. 440. _Definition._--#Pylobotryida# with tubes on the cephalis, and with the mouth of the abdomen open. The genus _Pylobotrys_ differs from the closely allied _Acrobotrys_, its ancestral form, in the development of an abdomen or a third shell-joint, the basal mouth of which remains open. 1. _Pylobotrys putealis_, n. sp. (Pl. 96, fig. 21). Cephalis multilobate, with a single curved and descending tube on the base of its anterior part (sternal tube). Occipital half of the cephalis divided into three large odd lobes (the largest {1122}the apical); facial half divided into three to five lobes, an odd frontal and one or two lateral pairs of small buccal lobes. Thorax truncate conical, about as large as the cephalis and larger than the truncate abdomen. Pores regular circular. _Dimensions._--Length of the shell 0.12, breadth 0.08. _Habitat._--Tropical Atlantic Station 347, depth 2250 fathoms. 2. _Pylobotrys fontinalis_, n. sp. (Pl. 96, fig. 20). Cephalis trilobate, with three ovate lobes in the sagittal plane, of nearly equal size, and two divergent cylindrical tubes conical at the base. An ascending apical tube on the apex of the occipital lobe and a descending sternal tube on the base of the frontal lobe. The middle lobe between the former distinctly exhibits in the apical view (fig. 20) the collar septum with the four cortinar pores. Thorax campanulate, larger than the cephalis and the truncate abdomen. _Dimensions._--Length of the shell 0.11, breadth 0.06.