Shell ellipsoidal, one and a half times as long as broad, on the apical pole hemispherical, on the basal pole coronate, with an elegant prominent funnel-shaped peristome, which is one-eighth as broad as the shell, fenestrated by very fine pores, and bears fifteen to twenty short conical divergent teeth. Inner shell with irregular polygonal meshes of very different size, separated by thin, {1173}finely-denticulate bars. Outer spongy shell very delicate, arachnoidal, with numerous prominent conical spongy papillæ. Central capsule ellipsoidal, half as long and broad as the shell. _Dimensions._--Shell 0.46 long, 0.32 broad; mouth 0.045 broad. _Habitat._--Central Pacific, Stations 271 to 274, surface. 2. _Arachnocalpis sphæroides_, n. sp. Shell spheroidal, of the same structure as the preceding ellipsoidal species, with the same form of the spongy envelope; differing from it in the globose form and the shorter peristome, bearing only nine or ten small conical divergent teeth. Central capsule spherical. _Dimensions._--Shell 0.3 diameter, mouth 0.04 broad. _Habitat._--Central Pacific, Stations 265 to 270, surface. Subfamily 2. ARCHIPHÆNIDA, Haeckel, 1881, Prodromus, p. 429. _Definition._--#Phænocalpida# with the basal mouth of the shell fenestrated (vel Monocyrtida multiradiata clausa). Genus 522. _Phænocalpis_,[139] n. gen. _Definition._--#Archiperida# (vel Monocyrtida multiradiata clausa) with an internal axial simple columella, prolonged outside into an apical horn. The genus _Phænocalpis_ and the following _Phænoscenium_ comprise those Archiphænida in which the vertical axis of the shell-cavity is occupied by a simple or branched columella, arising from the centre of the base and prolonged into an apical horn. This columella may be either the vertical rod of a _Plectaniscus_ or the remnant of an original ring of _Petalospyris_. The latter genus differs by its sagittal constriction. 1. _Phænocalpis petalospyris_, n. sp. (Pl. 97, fig. 4). Shell subspherical, rough, with irregular, roundish pores, larger than the bars. Columella straight, central, thin, prolonged into a large apical horn with three dentate edges. Six basal feet curved, divergent, lamellar, with a middle rib and dentate edges. _Dimensions._--Shell 0.07 long, 0.05 broad; horn and feet 0.06 long. _Habitat._--Tropical Atlantic, Station 347, depth 2250 fathoms. {1174}2. _Phænocalpis ocellata_, Haeckel. _Petalospyris ocellata_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 9. Shell subspherical, smooth, with irregular roundish pores, about as broad as the bars. Columella slightly curved and excentric, prolonged into a slender conical horn of the same length. Six basal feet similar to the horn, slightly divergent. _Dimensions._--Shell 0.06 long, 0.07 broad; horn and feet 0.05 long. _Habitat._--Fossil in Barbados. 3. _Phænocalpis carinata_, Haeckel.