REPORT ON THE RADIOLARIA. 525 



Ditncnsions. — Eadius of each arm (length from the centre to the distal end) 013; breadth of the 

 truncated end 01. 



Hcibitat. — Tropical Pacific, Philippine Sea, Station 200, depth 250 fathoms. 



2. Dictyastrum handaicum, Haeckel. 



Rhopdlastrum handaicum, Harting, 1863, Jlikr. Fauna Banda-Zee, p. 16, Taf. iii. fig. 45. 



Arms nearly square, with couve.x edges, in the middle a little broader than at both ends, about 

 half the diameter of the central disk. Differs from the nearly allied jireceding species by the 

 half size of the arms and the convex edges. 



Dimensions. — Eadius of each arm 0'12, its greatest breadth 0'07. 



Habitat. — Tropical Pacific, Banda Sea, Harting. 



3. Dictyastrum liexagonum, n. sp. (PL 43, fig. 7). 



Rhopdlastrum liexagonum, Haeckel, 1880, Atlas (pi. xliii. fig. 1). 



Arms nearly triangular, one and a third times as broad at the distal end as long, and three 

 times as broad as at the base. Central disk about the same diameter. In each arm six simple 

 broad chambers. If we connect the six corners of the truncated distal ends by straight lines, we 

 get a regular hexagon. 



Dimendons. — Eadius of each arm-0"l7, basal breadth 0"06, terminal breadth 0'17. 



Habitat. — Equatorial Atlantic, Station 347, surface. 



4. Dictyastrum. trirrhopalum, n. sp. 



Arms club-shaped, five times as long as broad at the base, at the thickened end three times 

 as broad as at the base. Diameter of the central disk equals half the length of the arms. 

 (Similar to Rho2mlastrum, malleus, PL 43, fig. 1, but with three equal angles and much smaller disk.) 



Dimensions. — Eadius of each arm 0'25, basal breadth 0*04, distal breadth 0-12. 



Habitat. — Pacific, central area. Station 273, surface. 



Subgenus 2. Dictyastromma, HaeckeL 

 Definition. — Arms on the distal end provided with terminal spines. 



5. Dictyastrum trispinosum, n. sp. (PL 43, fig. 5). 



Rhopalastrum trispinosum, Haeckel, 1881, Prodromus et Atlas (pi. .xliii. fig. 5). 



Arms trapezoid, at the rounded distal end twice as broad as at the base, with a strong and 

 short, conical, terminal spine. Diameter of the cu-cular central disk about equal to the length and 

 the greatest breadth of the arms. 



Dimensions. — Eadius of each arm 0'15, basal breadth 0'06, distal breadth Oil. 



Habitat. — Equatorial Atlantic, Station 347, surface. 



