REPORT ON THE RADIOLARIA. 379 



Subgenus 2. Panartissa. 



Definition. Surface of the cortical shell smooth, without spines or thorns. Both 

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



6. Panartus diploconus, n. sp. (PI. 40, fig. 1). 



Both proximal chambers nearly ellipsoidal, one and a half times as broad as long, with regular 

 hexagonal pores, four times as broad as the bars ; five to six pores on the half meridian, nine to ten 

 on the half equator of each chamber. Both distal chambers conical, with a circle of ten to twelve 

 large square pores at the base ;. the other pores very small and numerous, roundish, sixteen to 

 twenty in the height of each cone, and the same number on the half periphery of its base. Both 

 concentric medullary shells compressed, the outer, half as broad as the constriction of the cortical 

 shell, the surface of which is quite smooth. 



Dimensions. Total length of the shell (or main axis) 0'34 ; greatest breadth of each chamber 

 0'09 ; pores of the proximal chambers 0013, bars O003 ; pores and bars of the distal chambers 

 O003 ; large basal square pores 0'02. 



Habitat. Pacific, central area, Station 272, depth 2600 fathoms. 



7. Panartus amphiconus, n. sp. 



Both proximal chambers nearly kidney-shaped, one and a half times as broad as long, with 

 regular, circular pores, with hexagonal frames, twice as broad as the bars ; six to seven pores on the 

 half meridian, ten to twelve on the half equator of each chamber. Both distal chambers conical, 

 with a circle of ten to twelve very large pores at the base ; the other pores very small, roundish, 

 ten to fifteen in the height of each cone, twenty to thirty on the half basal periphery. Both 

 concentric medullary shells compressed, the outer one-third as broad as the constriction of the 

 cortical shell, whose surface is smooth. (This species resembles Peripanartus amphiconus, PI. 40, fig. 5, 

 but is without the surface spines and the outer envelope.) 



Dimensions. Total length of the shell 0'28 ; greatest breadth of the proximal chambers 01, of 

 the distal chambers 014 ; pores of the former O'OOS, of the latter 0'004 ; bars of both 0'003 to 0"005. 



Habitat. North Pacific, Station 244, depth 2900 fathoms. 



8. Panartus fusif or mis, n. sp. 



Both proximal chambers nearly ellipsoidal, one and a half times as long as broad, with irregular, 

 roundish pores, twice to three times as broad as the bars ; eight to ten pores on the half meridian, 

 twelve to fifteen on the half equator of each chamber. Both distal chambers hemiellipsoidal or egg- 

 shaped, somewhat higher and narrower than the proximal chambers, with a circle of larger square 

 pores at their base ; the other pores roundish and very irregular. Both medullary shells spheroidal, 

 one-third as broad as the constriction of the cortical shell, whose surface is quite smooth. (This 



