REPORT ON THE RADIOLARIA. 521 



6. Amphymenium fusiforme, n. sp. 



Both arms equal, lanceolate, three times as long as broad in the width, with seven to eight 

 joints. Distal end pointed, armed with a strong conical terminal spine. Patagium complete, 

 enveloping the whole shell with exception of the terminal spines. Whole form spindle-shaped. 



Dimensions. Radius of each arm 0'2, greatest breadth O'OV ; transverse breadth of the 

 patagium 015. 



Habitat. South Atlantic, Station 330, surface. 



Genus 225. Amphirrhopalum, 1 Haeckel, 1881, Prodromus, p. 460. 



Definition. Porodiscida with two chambered arms, opposite in one axis, 

 without a patagium; one arm or both forked at the distal end. 



The genus Amphirrhopalum differs from Amphibrachium, its ancestral form, by 

 bifurcation of the distal ends of the arms, which may affect either both arms, or only 

 one of them. 



Subgenus 1. Amphirrhopalium, Haeckel. 



Definition. Both opposite anus of similar size and form, with blunt branches, 

 without terminal spines. 



1. Amphirrhopalum ximorphum, n. sp. 



Both arms equal, in the proximal half simple, in the distal half forked, with six to seven 

 transverse septa ; distal end of each branch blunt, without terminal spine, somewhat broader than 

 the base of the whole arm. Axis of the branches concavely curved. (Eesembles Amphicraspedum 

 madaganium, PI. 45, fig. 11, but wants the patagium.) 



Dimensions. Eadius of the arms 018, basal breadth 0'065 ; terminal breadth of each 

 branch 0'075. 



Habitat. North Pacific, off Japan, Station 240, surface. 



2. Amphirrhopalum amphidicranum, n. sp. 



Both arms equal, in the proximal half simple, in the distal half forked, with irregular septa ; 

 distal end of each arm blunt, without a terminal spine, smaller than the basal breadth of the arm. 

 Axis of the branches straight. (Resembles Dicranastrum furcatum, PL 47, fig. 2, but without 

 lateral arms.) 



Dimensions. Radius of each arm 015, basal breadth 0'03; terminal breadth of each branch 0'02. 



Habitat. Pacific, central area, Station 263, depth 2650 fathoms. 



1 Amphirrhopalum = Shell with clubs on both sides ; *nQi, fV*Xo. 

 (ZOOL. CHALL. EXP. PART XL. 1885.) Rr 66 



