132 THE VOYAGE OF H.M.S. CHALLENGER 



Dimensions. Diameter of the sphere 0'07, pores 0'005, hars 0'0025 ; diameter of the circular 

 ring 0'2, thickness, of the axial beams and the ring O'Ol. 



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



2. Saturnalia annularis, n. sp. (PL 13, fig. 16). 



Pores of the spherical shell regular, circular, with elevated hexagonal frames, of the same 

 breadth as the bars. Sixteen to twenty pores on the half equator. Eing elliptical, smooth, some- 

 what constricted at the poles of the axis, its diameter three times as great as that of the sphere. 



Dimensions. Diameter of the sphere 0'09, pores and bars 0'005, major axis of the elliptical 

 ring 0'27 to 0'03, minor axis 019 to 0'2 ; thickness of the ring and of the axial beams O'Ol. 



Habitat. Pacific, central area, Stations 270 to 274, surface. 



3. Saturnalia cyclus, n. sp. 



Lithocirais mesocena, Bury, 1862, Polycystins of Barbados, pi. iii. fig. 1. 



Pores of the spherical shell regular, circular, without hexagonal frames, twice as broad as the 

 bars Eight to ten pores on the half equator. Eing circular, smooth, its diameter four times as 

 great as that of the sphere. 



Dimensions. Diameter of the sphere 0'07, pores O'OOG, bars 0'003 ; diameter of the circular 

 ring 0'28, thickness of the ring and both axial beams O'Ol. 



Habitat. Fossil in the Barbados rocks. 



4. Saturnalis circoides, n. sp. (PI. 13, fig. 12). 



Pores of the spherical shell irregular, roundish, often somewhat lobed, one to three times as 

 broad as the bars ; fifteen to twenty on the half equator. Eing circular, smooth, with four promi- 

 nent edges, its diameter twice as great as that of the sphere. (The figured specimen is a young 

 or not fully developed one ; afterwards I found in the same locality other specimens with quite 

 perfect rings, similar to the edged ring of Saturnulus annulus, PL 16, fig. 17.) 



Dimensions. Diameter of the sphere 0'09 to 01, pores 0'003 to O'Ol, bars 0'004; diameter 

 of the circular ring 0'2 to 0'24, thickness of the ring and the polar beams O'Ol. 



Habitat. Indian Ocean ; fossil in the Nicobar rocks ; living at great depths near Zanzibar, 

 2200 fathoms, Pullen. 



Subgenus 2. Saturnalium, Haeckel. 

 Definition. Ring armed on the periphery with numerous spines or thorns. 



5. Saturnalis trochoides, n. sp. 



Haliomma species, Bury, 1862, Polycystins of Barbados, pi. xx. fig. 2. 



Pores of the spherical shell subregular, circular, twice as broad as the bars. Twelve to sixteen 

 pores on the half equator. Eing circular, armed with ten to twelve strong conical, irregular spines, 

 its diameter twice as great as that of the sphere. 



