REPORT ON THE RADIOLARIA. 215 



Dimensions. Diameter of the shell 013, larger pores 0'03, smaller 0'003 ; length of the 

 spines - 03. 



Habitat. Mediterranean (Nice), surface. 



22. Acanthosphcera longispina, n. sp. 



Shell thin walled, with irregular polygonal meshes, four to six times as broad as the bars ; six 

 to eight on the radius. Thirty to forty radial spines, three-sided prismatic, twice as broad as the 

 bars, twice to three times as long as the diameter of the shell. 



Dimensions. Diameter of the shell 012 to 015, pores O012 to 0'02, bars 0'003 ; length of the 

 radial spines 02 to 0'4, breadth 0-006. 



Habitat. North Pacific, Station 253, surface. 



23. Acanthosphcera brevispina, n. sp. 



Shell thick walled, with irregular polygonal meshes, twice to four times as broad as the bars ; 

 twelve to sixteen on the radius. Sixty to eighty radial spines, pyramidal, half as long as the radius 

 of the shell, one-fourth as broad at the base. 



Dimensions. Diameter of the shell 0'2 to 0'22, pores O'OOG to 0'012, bars 0'003 ; length of the 

 spines 0'05, basal breadth 0'02. 



Habitat. Central Pacific, Station 268, depth 2900 fathoms. 



24. Acanthosphcera acanthica, Haeckel. 



Cenosphcera acanthica, Stohr, 1880, Palseontogr., vol. xxvi. p. 86, Taf. i. fig. 3. 



Shell thick walled, with irregular, roundish pores, twice to three times 'as broad as the bars ; 

 seven to nine on the radius. Ten to twenty radial spines pyramidal, shorter than the radius, 

 twice as broad at the base as one mesh. 



Dimensions. Diameter of the shell 012 to 016, pores 0'006 to 0'009, bars O'OOS ; length of 

 the spines 0'04 to 0'06, basal breadth O'Ol to 0'015. 



Habitat. Fossil in Tertiary rocks of Sicily and Barbados. 



25. Acanthosphcera, haliphormis, Ehrenberg. 



Acanthosphcera haliphormis, Ehrenberg, 1861, Abhandl. d. k. Akad. d. Wiss. Berlin, 1872, Taf. ii. 

 fig. 1. 



Shell thick walled, with irregular, roundish pores, twice to four times as broad as the bars ; four 

 to five on the radius. Twelve to twenty radial spines pyramidal, longer than the radius, scarcely 

 as broad as one mesh at the base. 



Dimensions. Diameter of the shell Oil, pores O'Ol to 0'02, bars 0'005 ; length of the spines 

 0-06 to 0-08, basal breadth O'Ol. 



Habitat. Arctic Ocean, near Greenland, depth 1000 fathoms. 



