REPORT ON THE RADIOLARIA. 439 



seven or nine, more or less irregular), conical, about as long as the diameter of the disk, without 

 a connecting equatorial girdle. 



Di-mensions. — Diameter of the disk 0'15, of the medullary shell O'fln ; length of the radial 

 spines 0'16, basal breadth O'Ol. 



Habitat. — Pacific, central area. Station 271, depth 2425 fathoms. 



3. Heliosestrum solarium, Haeckel. 



Haliomma sol (jpartim), Ehrenberg, 1875 {non 1844), Abhandl. d. k. Akail. d. Wiss. Berlin, 

 I). 74, Taf. xxviii. fig. 1. 



Surface of the disk smooth ; its diameter six times as large as that of the medullary shell. 

 I'ores regular, circular ; nine to ten on the radius. Eight marginal spines regularly distributed 

 (sometimes seven or nine, more or less irregular), conical, about as long as the diameter of the 

 medullary shell, without a connecting equatorial girdle. 



Dimensions. — Diameter of the disk 0'18, of the medullary shell 0'03 ; length of the radial 

 spines O^OS, basal breadth O'Ol. 



Habitat. — Fossil in the Tertiary rocks of Barbados. 



4. Heliosestrum Uriope, n. sp. 



Surface of the disk smooth ; its diameter four times as large as that of the medullary shell. 

 Pores subregular, circular ; seven to eight on the radius. Eight marginal spines regularly distributed, 

 conical, compressed, alternating longer and shorter ; the longer equal to the diameter of the disk, 

 the shorter to the radius. 



Dimensions. — Diameter of the disk 016, of the medullary shell 04 ; length of the major radial 

 spines 0"15, of the minor 0'09. 



Habitat. — North Pacific, Station 236, surface. 



5. Ilehosesti'um quadrigeininum, n. sp. 



Surface of the disk smooth ; its diameter four times as large as that of the medullary shell. 

 I'ores irregular, roundish ; six to seven on the radius. Eight marginal spines triangular, flat, regularly 

 disposed, alternating longer arid shorter, the major as long as the radius of the shell, and half as 

 broad at the base, with three to four deep furrows on both sides, without a connecting equatorial gu-dle. 



Dimensions. — Diameter of the disk 0'16, of the medullary shell 0-04 ; length of the larger radial 

 spines O'OS, of the smaller 0-04, basal breadth 0-04. 



Habitat. — Pacific, central area, Station 266, depth 2750 fathoms. 



6. Heliosestnim contiguum, Haeckel. 



Haliomma contiguum, Ehrenberg, 1875, Abhandl. d. k. Akail. d. Wiss. BerHn, p. 74, Taf. xxvii. 



fig. 5. 



Disk with smooth surface, four times as broad as the medullary shell. Pores iiTegular. 

 roundish, touching, with very thin bars ; nine to ten on the radius. Eight marginal spines (often 



