REPORT ON THE RADIOLARIA. 1687 



3. Castanissa richardsi, n. sp. 



Pores subregular, circular, about as broad as the bars. Bristles twice as long as one pore. 

 Radial main-spines (about twenty) slender, cylindrical, irregularly curved, with dimpled surface (like 

 those in PI. 113, fig. 5a). Mouth with a corona of six stout, parallel, triangular teeth. 



Dimensions. Diameter of the shell 0'3 to 0'35, of the pores 0'015. 



Habitat. North Atlantic, Station 354, surface. 



4. Castanissa crosbiei, n. sp. 



Pores irregular, roundish, two to three times as broad as the bars. Bristles one-third as long 

 as the radius. Eadial main-spines very numerous, straight, cylindrical, smooth, about as long as 

 the diameter of the shell. Mouth with ten or twelve irregular, conical, parallel teeth. 



Dimensions. Diameter of the shell 0'28, of the pores O'Ol to 0'015. 



Habitat. North Pacific, Stations 231 to 235, surface. 



5. Castanissa macleani, n. sp. 



Pores irregular, roundish or polygonal, two to four times as broad as the bars. Bristles about 

 one-fourth as long as the radius. Eadial main-spines numerous, straight, conical, stout, with 

 dimpled surface, shorter than the radius. Mouth with six to eight irregular conical teeth. 



Dimensions. Diameter of the shell 032, of the pores 0'012 to 0'024. 



Habitat.- Tropical Pacific, Station 268, depth 2900 fathoms. 



6. Castanissa hoylei, n. sp. 



Pores irregular, polygonal, two to three times as broad as the bars. Bristles nearly half as 

 long as the radius. Eadial main-spines (about thirty) very long and thin, cylindrical, irregularly 

 curved, at the conical base inflated and fenestrated ; shell therefore slightly polyhedral. Mouth 

 with five strong conical teeth. 



Dimensions. Diameter of the shell 0'35 to 0'4, of the pores 0'02 to 0'03. 



Habitat. North Pacific, Station 245 to 250, surface. 



Genus 709. Castanopsis, 1 Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. 



Jena, Dec. 12, p. 5. 



Definition. Cas tanellida with branched radial main-spines and a simple 

 smooth mouth. 



The genus Castanopsis differs from its ancestral form Castanidiutn in the ramifica- 

 tion of the radial main-spines ; the branches are usually very irregular and often partly 



1 Castanopsis = Shell similar to a chestnut ; xciimti/o>i, Ifyis. 



