REPORT ON THE RADIOLARIA. 381 



fourteen on the half equator of each chamber. Surface spiny, everywhere covered with small 

 irregular thorns. (This species differs from the smooth Panartus tetrathalamus, PI. 40, fig. 3, almost 

 entirely by the thorny surface.) 



Dimensions. Main axis 0'2, equatorial axis 0'08 ; breadth of every chamber O'l ; meshes O005 

 to O'Ol, bars 0'003, spines O'Ol to 0'02. 



Habitat. Cosmopolitan ; on the surface of the Atlantic, Indian, and Pacific Oceans. 



12. Panartus quadrigeminus, n. sp. 



All four chambers of the cortical shell nearly of the same size and form, kidney-shaped, twice 

 as broad as long. Pores irregular, polygonal (mostly pentagonal or hexagonal), six to eight times as 

 broad as the thin bars ; five to seven on the half meridian, twelve to sixteen on the half equator of 

 each chamber. Surface of the cortical shell spiny, covered with numerous irregularly scattered, 

 often oblique, bristle-like thorns. 



Dimensions. Main axis 0'27, equatorial axis O'l ; breadth of each chamber 0'13 ; meshes O'Ol 

 to 0'02, bars O'OOl to 0'005. 



Habitat. Cosmopolitan ; surface of the Atlantic and Pacific, many Stations. 



Subgenus 4. Panartura, Haeckel. 



Definition. Surface of the cortical shell thorny, covered with scattered spines. 

 Both its proximal chambers differ in form or structure from the two distal chambers. 



13. Panartus spinosus, n. sp. 



Both proximal chambers nearly ellipsoidal, with regular, circular pores enclosed by hexagonal 

 frames. Both distal chambers conical, with a circle of ten to twelve large square pores at the 

 base ; the other pores small, roundish. The cortical shell of this species is quite the same as that 

 of Panartus amphiconus (PL 40, fig. 5), but differs in the absence of the external envelope (or the 

 second cortical shell), and is covered with short, conical spines on the whole surface. 



Dimensions. Total length of the cortical shell 0'25, greatest breadth (on the base of the distal 

 chambers) 0'12 ; meshes of the proximal chambers O'OOS, of the distal chambers 0'004 ; bars 0'002 

 to 0-04, spines O'Ol to 0'02. 



Habitat. North Pacific, Station 240, surface. 



14. Panartus setosus, Haeckel. 



Ommatocampe setosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. viii. 

 fig. 7. 



Both proximal chambers kidney-shaped, broader than the two hemispherical distal chambers. 

 Meshes of the cortical shell irregular, polygonal, or subregular hexagonal ; at the base of each 



