REPORT ON THE RADIOLARIA. 587 



5. Spongotrochus par ma, n. sp. 



Spongy framework of the disk in the inner part with five to eight spiral convolutions (or partly 

 concentric rings), in the outer part quite irregular. Thirty to forty long, bristle-shaped, radial spines, 

 about as long as the diameter of the disk, disposed on both flat sides of the disk, but not on the 

 margin. 



Dimensions. Diameter of the disk 016 ; length of the radial spines 018, basal breadth O'OOS. 



Habitat. South Atlantic, Station 325, surface. 



Subfamily 3. SPONGOBRACHIDA, Haeckel, 1881, Prodromus, p. 461. 



Definition. S pongodiscida with two or more (commonly three or four) 

 spongy radial arms on the margin of the disk, situated in its equatorial plane (with or 

 without a connecting patagium between the arms). 



Genus 260. Spongolena, 1 n. gen. 



Definition. S pongodiscida with two opposite spongy arms on the margin of 

 the disk, without a connecting patagium. 



The genus Spongolena opens the series of -the Spongobrachida, or of the 

 Spongodiscida provided with radial spongy arms on the margin of the disk. Spongolena 

 is the most simple form of this subfamily, and bears only two simple opposite arms, 

 without a connecting patagium. It corresponds to Amphibrachium (Porodiscida) and 

 to Diplactura (Coccodiscida). Also there is no patagium. Spongolena may easily be 

 confounded with Spongurus (compare my Prodromus, 1881, p. 461); but in the true 

 Spongurus (an ellipsoid) the transverse section is circular, in Spongolena elliptical. 



1. Spongolena rhopalura, n. sp. 



Arms club-shaped, three times as long as broad, at the rounded distal end twice as broad as at 

 the base, and twice as long as the diameter of the circular central disk. Surface nearly smooth. 



Dimensions. Radius of the arms (or the distance from the centre to the distal arm-end) 016, 

 distal breadth 0'05, basal breadth 0'03. 



Habitat. Pacific, central area, Station 273, depth 2350 fathoms. 



2. Spongolena spongura, n. sp. 



Arms nearly cylindrical, twice as long as broad, and a little longer than the diameter of the 

 elliptical central disk. Surface thorny, some longer bristle-shaped spines on the distal end of the 



1 Spongolena = Spongy disk with two arms; a^oyyo;, uh'.uit. 



