Cephalis quinquelobate, with a single conical apical tube of the same length, which has an obliquely truncate frontal opening. Odd frontal and paired buccal lobes smaller than the sternal and the occipital lobe. Internal frontal septum with six large pores. Thorax inflated, a little larger than the subspherical abdomen. Pores subregular, circular. _Dimensions._--Length of the shell 0.15, breadth 0.08. _Habitat._--Central Pacific, Station 272, depth 2600 fathoms. {1125}3. _Phormobotrys hexathalamia_, Haeckel. _Botryocampe hexathalamia_, Haeckel, 1862, Monogr. d. Radiol., p. 344, Taf. xii. fig. 10. Cephalis sexlobate, with a single apical horn, which is solid, vertical, cylindrical, pointed, only one-third as long. Frontal lobes subcylindrical, nearly as long as the kidney-shaped occipital lobe, three to four times as long as the small buccal lobes and the odd sternal lobe. Thorax tun-shaped, smaller than the cephalis, larger than the hemispherical abdomen. Pores numerous, subregular, circular. _Dimensions._--Length of the shell 0.13 to 0.15, breadth 0.05 to 0.06. _Habitat._--Mediterranean, Messina, surface. 4. _Phormobotrys cannothalamia_, n. sp. (Pl. 96, fig. 25). Cephalis trilobate, of about the same breadth and length as the campanulate thorax, which is three times as long as the flat cap-shaped abdomen. The middle (or central) lobe of the cephalis is simple, nearly cubical, and smaller than the ovate occipital and frontal lobe. The two latter are prolonged into two slender cylindrical divergent tubes. Pores small and very numerous. _Dimensions._--Length of the shell 0.1, breadth 0.05. _Habitat._--Western Tropical Pacific, Station 225, depth 4475 fathoms. 5. _Phormobotrys polythalamia_, n. sp. Cephalis multilobate, of the same length and breadth as the subspherical thorax, and half as long as the ovate abdomen. Occipital lobe helmet-shaped, about as large as the frontal half of the cephalis, which is divided into six to eight lobes (two odd and two or three pairs of lateral lobes). Four cylindrical tubes corresponding to the four typical spines of _Cortina_, an ascending apical and three descending basal tubes (a posterior caudal and two anterior pectoral). _Dimensions._--Length of the shell 0.14, breadth 0.08. _Habitat._--South Pacific, Station 298, depth 2225 fathoms. {1126}---- Suborder III. CYRTOIDEA, Haeckel, 1862. _Cyrtida_, Haeckel, 1862, Monogr. d. Radiol., pp. 272, 280. _Cyrtoidea_ vel _Cyrtida_, Haeckel, 1881, Prodromus, pp. 425-439. _Polycystina solitaria_, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, pp. 53, 54. _Monodictya nassellaria_, Ehrenberg, 1875, Abhandl. d. k. preuss. Akad. d. Wiss. Berlin, pp. 156, 157. _Definition._--NASSELLARIA with a complete lattice-shell, exhibiting a simple or reduced cephalis, which is neither bilocular nor lobate, without sagittal constriction.