Shell slender, conical, nearly cylindrical, with straight outlines, rounded at the apex. Pores very small and numerous, punctiform, disposed into very numerous parallel transverse rows. Horn small, conical (may be perhaps the shell of a Tintinnoid Infusorium?). _Dimensions._--Shell 0.08 long, 0.02 broad. _Habitat._--North Pacific, Californian Sea, depth 2600 fathoms. 10. _Cornutella annulata_, Ehrenberg. _Cornutella annulata_, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. ii. fig. 16. Shell slender, conical, nearly cylindrical, with straight outlines, rounded at the apex. Pores small and numerous, regular circular, of equal size, regularly disposed in ten to fifteen parallel transverse series. Horn bristle-shaped. (Compare _Artostrobus annulatus_, _Cornutella annulata_, Bailey.) _Dimensions._--Shell 0.1 to 0.13 long, 0.03 to 0.04 broad. _Habitat._--Cosmopolitan, Atlantic, Pacific, surface. {1183}Subgenus 3. _Cornutosa_, Haeckel, 1881, Prodromus, p. 427. _Definition._--Axis of the conical shell curved. Pores circular or roundish. 11. _Cornutella curvata_, Haeckel. _Cornutella clathrata_, var., Ehrenberg, 1854, Mikrogeol., Taf. xxii. figs. 39_a_, _b_, _c_. _Cornutosa clathrata_, Haeckel, 1881, Prodromus, p. 427. Shell slender, conical, with curved axis; the curve lies in one plane and is not spirally convoluted. Pores subregular, circular, of nearly equal size, quincuncially disposed. Horn short, conical. _Dimensions._--Shell 0.1 to 0.15 long, 0.04 to 0.06 broad. _Habitat._--Fossil in tertiary rocks of Sicily (Caltanisetta). 12. _Cornutella spiralis_, n. sp. _Cornutura spiralis_, Haeckel, 1881, Prodromus, p. 427. Shell slender, conical, nearly cylindrical, very long, spirally contorted; its axis is an ascending spiral line with two or three windings, widely distant. Pores irregular, square, small and numerous. _Dimensions._--Shell 0.2 to 0.25 long, 0.05 to 0.08 broad. _Habitat._--Central Pacific, Station 271, depth 2425 fathoms. Genus 527. _Cornutanna_,[144] Haeckel, 1881, Prodromus, p. 427. _Definition._--#Archicorida# with conical shell, gradually dilated towards the wide open mouth. Apex without horn. The genus _Cornutanna_ has the same simple conical shell as the preceding _Cornutella_, but differs from it in the total absence of an apical horn. It bears therefore to the latter the same relation that _Cyrtocalpis_ does to _Archicorys_. It may be derived from _Sethoconus_ by complete reduction of the cephalis and its horn. 1. _Cornutanna orthoconus_, n. sp. Shell slender, conical, with straight axis and straight outlines. Pores subregular, circular, quincuncially disposed in nine to twelve alternating longitudinal series, gradually increasing in size towards the mouth. _Dimensions._--Shell 0.1 to 0.12 long, 0.03 to 0.04 broad. _Habitat._--Central Pacific, Stations 270 to 274, surface. {1184}2. _Cornutanna cyrtoconus_, n. sp.