REPORT ON THE RADIOLARIA. 467 



chambers. Pores regular, circular ; seven on the radius of the phacoid shell, one single pore on 

 each chamber (the size increasing from the centre). Margin with thirty to forty angular, broad, 

 dentate spines, the prolongations of the inner radial beams. 



Dimensions. Diameter of the disk (with six rings) 0'22, of the phacoid shell O'l, of the 

 medullary shell O04. 



Habitat. Pacific, central area, Station 268, depth 2900 fathoms. 



2. Astrocyclia Stella, Haeckel. 



Lithocydia stella, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. xxix. 

 fig. 2. 



Phacoid shell three times as broad as the medullary shell, surrounded by four to eight rings of 

 increasing breadth from the centre, the outer of which are more or less spongy. Each ring is 

 divided by forty to fifty piercing radial beams into chambers of increasing size. Pores regular, 

 circular ; a single one on each chamber, ten on the radius of the phacoid shell. On the margin 

 are scattered ten to twenty thick and short spines, four-sided pyramidal, about as long and as broad 

 at the base as the diameter of the medullary shell. 



Dimensions. Diameter of the disk (with eight rings) 0'25, of the phacoid shell 0'09, of the 

 medullary shell 0'03. 



Habitat. Fossil in the rocks of Barbados. 



3. Astrocyclia rotula, n. sp. 



Phacoid shell four times as broad as the medullary shell, surrounded by one single ring, which 

 is divided by forty radial beams into equal chambers. Pores regular, circular; two on the breadth 

 of the ring, six on the radius of the phacoid shell. Margin with forty short, conical spines, the pro- 

 longations of the inner radial beams, twice as long as the breadth of the ring. 



Dimensions. Diameter of the disk 0'13, of the phacoid shell O'l, of the medullary shell 0'025. 



Habitat. South Atlantic, Station 332, depth 2200 fathoms. , 



4. Astrocyclia arachnia. n. sp. 



Phacoid shell twice as broad as the medullary shell, surrounded by four to six rings of equal 

 breadth, which are divided by twelve to twenty radial beams into broad chambers. Pores regular, 

 circular ; two on the breadth of each ring, eight on the radius of the phacoid shell Margin with 

 twelve to twenty very long and thin, bristle-shaped, radial spines, the prolongations of the inner 

 beams, longer than the diameter of the disk. (Resembles Stylodictya arachnia, but differs in the 

 possession of a phacoid shell.) 



Dimensions. Diameter of the disk (with six rings) 0'22, of the phacoid shell 0'09, of the 

 medullary shell 0'045. 



Habitat. North Atlantic, Canary Islands. 



