REPORT ON THE RADIOLARIA. 251 



Subgenus 2. Astrosphceromma. 



Definition. — Radial maiu spines with three rows of Literal branches (one row on 

 each edge). 



3. AstrosphxBra sideroea, n. sp. 



Inner shell with regular, hexagonal meshes, six times as broad as the bars, and covered with 

 numerous short bristle-shaped by-spines ; outer shell four times as broad, with simple triangular 

 meshes, and rows of long bristle-shaped' by-spines arising from the bars. Eadial main spines with 

 three serrated edges and three rows of lateral branches (four branches on each edge). 



Dimensions. — Diameter of the outer shell 0'6, inner 0"15. 



Habitat. — Central Pacific, Station 266, surface. 



4. Astros]}h(era stellata, n. sp. (PL 19, fig. 5). 



Diplosphcera stellata, Haeckel, 1881, Prodrom. et Atlas. 



Inner shell with regular, hexagonal, six-rayed meshes, each bar being crossed by a transverse 

 tangential rod, at each nodal-point a long bristle-shaped by-spine ; outer shell three times as 

 broad, with simple triangular meshes and denticvdated thin liars, bearing a row of bristle-shaped 

 radial by-spines. Eadial main spines in the proximal half with three serrated edges, in the distal 

 half with three rows of curved lateral branches (five branches on each edge). 



Dimensions. — Diameter of the outer shell 0"6, inner 0'2. 



Habitat. — Central Pacific, Station 274, surface. 



Subfamily Actinommida,^ Haeckel, 1862, Monogr. d. Radiol., p. 440 (sensu emendato). 



Definition. — Astrosphasrida with three concentric, spherical, lattice-shells, 

 united by radial beams. 



Genus 101. Actinomma,^ Haeckel, 1862, Monogr. d. Radiol., p. 440. 



Definition. — A strospha^rida with three concentric lattice-spheres and numerous 

 simple radial spines of one kind. 



The genus Actinomma is here restiicted to those Sph^roidea which combine 

 the possession of three concentric lattice-shells with numerous radial spines on the 

 surface ; the spines are all simple, being of one and the same kind. Commonly two of 

 the three shells are intracapsular medullary shells, connected by radial beams {piercing 



1 Actinommidii = Astrosphferida triplicia = Triosphan'ida polyacantlm. 

 ^ Actinomvia = 'Radiaiit eye ; xkti's, oftfix. 



