338 THE VOYAGE OF H.M.S. CHALLENGER. 



spherical, about one-third as broad as the cortical, with simple circular pores. The connection 

 between the two shells is only made by two simple opposite beams, lying in the equatorial axis. 



Dimensions. Middle spheroidal part of the cortical shell 014 to 016 ; polar tubes 015 to 

 0'2 or longer, O03 broad ; pores and bars of the former 0'007, of the latter 0'003. Medullary 

 shell 0-04, pores 0'006, bars 0'003. 



Habitat. Western Tropical Pacific, Station 225, depth 4475 fathoms. 



3. Pipetta salpinx, n. sp. 



Cortical shell ellipsoidal, sharply separated from the cylindrical polar tubes, which reach about 

 the same length (or more). Network regular, with circular pores, three times as broad as the 

 bars, without hexagonal frames, fourteen to fifteen on the half equator. Pores of the polar tubes 

 smaller, arranged in eight to ten longitudinal rows. Medullary shell spherical, one-fourth as broad 

 as the cortical, connected with it by a circle of four to six radial beams, lying in the equatorial 

 plane. Differs from Pipettella prismatica (PI. 39, fig. 6) in the possession of a medullary shell and 

 the absence of the tube edges. 



Dimensions. Main axis of the ellipsoid 014, equatorial axis 012, pores O'Ol, bars - 003 ; length 

 of the tubes 015 or more, breadth 0'03. Medullary shell 0'03, pores 0-002, bars O'OOl. 



Habitat. Pacific, central area, Stations 265 to 268, depth 2700 to 2900 fathoms. 



4. Pipetta conus, n. sp. 



Cortical shell spindle-shaped, the middle ellipsoidal part gently passing over at both poles into 

 the conical tubes, which attain only half its length. Network irregular, with roundish or sub- 

 circular pores, twice to three times as broad as the bars, twelve to sixteen on the half equator. 

 Medullary shell spherical, one-fourth as broad as the cortical. (Differs from the foregoing species 

 in the short conical tubes and the irregular reticulation.) 



Dimensions. Middle part of the cortical shell 016 long, 013 broad ; tubes 0'09 long, 0'05 

 on the base broad ; pores 0'005 to O'Ol, bars 0'003. Medullary shell 0'04. 



Habitat. North Pacific, Station 241, depth 2300 fathoms. 



Genus 143. Pipettaria, 1 n. gen. 



Definition. D ruppulida with simple ellipsoidal cortical shell and double 

 medullary shell, with two hollow fenestrated tubes opposite on both poles of the main 

 axis. 



The genus Pipettaria differs from the foregoing Pipetta only in the duplication of 

 the medullary shell ; as in this, the tubular prolongations of the main axis of the 

 cortical shell may be either conical (with closed apex) or cylindrical (with apical 

 opening ?). 



1 Pipettaria = Pipetta-\ike. 



