Shell slender, conical, with straight outlines. Pores subregular, rhombic or nearly square, disposed in oblique series, separated by parallel obliquely ascending rings, which are crossed by interrupted parallel bars. Horn slenderly conical or bristle-shaped, thin and long. _Dimensions._--Shell 0.08 to 0.12 long, 0.03 to 0.04 broad. _Habitat._--Fossil in Barbados. Subgenus 2. _Cornutissa_, Haeckel, 1881, Prodromus, p. 427. _Definition._--Axis of the conical shell straight. Pores circular or roundish, without polygonal frames. 5. _Cornutella circularis_, Ehrenberg. _Cornutella circularis_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 4. Shell wide, conical or funnel-shaped, with straight outlines. Pores very large, circular, ten to twenty times as broad as the bars, in about nine to twelve longitudinal alternating rows, increasing gradually towards the mouth. Horn very large, cylindrical. _Dimensions._--Shell 0.1 to 0.15 long, 0.08 to 0.12 broad. _Habitat._--Fossil in Barbados. 6. _Cornutella mitra_, Ehrenberg. _Cornutella mitra_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. ii. fig. 8. Shell wide, conical, campanulate, with convex outlines. Pores subregular, circular, nearly equal in size, not regularly disposed in rows. Horn conical, stout. _Dimensions._--Shell 0.12 to 0.16 long, 0.08 to 0.12 broad. _Habitat._--Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados. {1182}7. _Cornutella clathrata_, Ehrenberg. _Cornutella clathrata_, Ehrenberg, 1838, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 129; Mikrogeol., Taf. xxii. fig. 39. _Cornutella clathrata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. ii. fig. 9. Shell wide, conical with slightly convex outlines. Pores regular, circular, gradually increasing in size towards the mouth, disposed in twelve to fifteen longitudinal alternating rows. Horn short and stout, conical. (Compare _Cornutella curvata_.) _Dimensions._--Shell 0.15 to 0.2 long, 0.06 to 0.09 broad. _Habitat._--Cosmopolitan; Atlantic, Indian, Pacific; also fossil in tertiary rocks of Barbados, Nikobar and Sicily. 8. _Cornutella stylophæna_, Ehrenberg. _Cornutella stylophæna_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. III. fig. 1. ? _Cornutella tumens_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. III. fig. 4. Shell slender, conical, with undulate outlines. Pores subregular, circular, gradually increasing in size, disposed in six to nine quincuncial alternating longitudinal rows. Horn very long, cylindro-conical, sometimes about as long as the shell. _Dimensions._--Shell 0.1 to 0.13 long, 0.04 to 0.06 broad. _Habitat._--North Pacific, Californian Sea, depth 2600 fathoms. 9. _Cornutella granulata_, Ehrenberg. _Cornutella granulata_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. vi. III. fig. 5.