356 THE VOYAGE OF H.M.S. CHALLENGEB. 



4. Artiscus panarius, n. sp. 



Pores of the shell irregular, roundish, twice to four times as broad as the bars ; sixteen to eighteen 

 pores on the half meridian, twelve to thirteen on the half equator. Surface smooth. 



Dimensions. Main axis of the shell O'll, equatorial axis 0'06 ; meshes - 005 to 0'02, bars 

 0-001 to 0-004. 



Habited. Western Tropical Pacific, Station 224, depth 1850 fathoms. 



Subgenus 2. Artidium, Haeckel, 1881, Prodromus, p. 462. 

 Definition. Surface of the shell covered with radial rods or spines. 



5. Artiscus elegans, n. sp. 



Pores of the shell regular, circular, with hexagonal frames, twice as broad as the bars ; fourteen 

 pores on the half meridian, eight to nine on the half equator. From every corner of the hexagonal 

 frames (between every three pores) starts a thin, three-sided pyramidal spine, twice as large as a 

 pore. 



Dimensions. Main axis 0'13, equatorial axis 0'08 ; meshes 0'007, bars 0'004 ; spines 

 0-015 long. 



Habitat. South Atlantic, Station 332, depth 2200 fathoms. 



6. Artiscus nodosus, n. sp. (PI. 39, fig. 9). 



Pores of the shell subregular, circular, without hexagonal frame, three times as broad as the 

 bars ; sixteen to eighteen on the half meridian, ten to twelve on the half equator. Irregularly 

 scattered on the whole surface a variable number (twenty-five to thirty in all) of stout short 

 radial spines or rather blunt rods ; the length and thickness of these is the same, and equals the 

 size of two to three meshes ; its form resembles a truncated six-sided pyramid. 



Dimensions. Main axis O'll, equatorial axis 0'08 ; meshes O'Ol, bars 0'003 ; length and 

 thickness of the radial sticks 0'02. 



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



7. Artiscus hystrix, n. sp. 



Pores of the shell irregular, roundish, of very unequal size and dissimilar form, twice to eight 

 times as broad as the bars; ten to fifteen on the half meridian, seven to nine on the half equator. 

 Irregularly scattered on the whole surface a large number of thin conical spines, about as large as 

 the meshes, partly directed radially, partly obliquely. (The shell of this species resembles very 

 much that of Cyplwnium ceratospyris (p. 366)= Didymocyrtis ecrato&pyris, Monogr. d. Ttadiol., 1862, 

 Taf. xxii. fig. 14, but is without the enclosed inner shells.) 



