REPORT ON THE RADIOLARIA. 191 



3. Hexaloncharium hystricinum, n. sp. 



Cortical shell spherical, three times as broad as the medullary shell, and densely covered with 

 oblique bristle-shaped by-spines. Pores irregular roundish. Two opposite major spines three-sided 

 prismatic, longer than the shell diameter ; four minor spines pyramidal, scarcely half as long as 

 the shell radius. (Somewhat similar to HexaloTwhe hystricina, but distinct in the prolongation of 

 two major spines.) 



Dimemions. — Diameter of the outer shell 0'15, inner 0-05 ; length of the two major spines 0-2, 

 four minor 0"03, basal breadth 0'02. 



Sahitat. — South Pacific, Station 288, surface. 



Genus 78. HexaloncMdium,^ Haeckel, 1881, Prodromus, p. 451. 



Definition. — C ubospliserida w\t\\ two concentric lattice-spheres and six simple 

 spines of diSerent sizes in pairs ; the two opposite spines of each paii' equal, the three 

 paii's unequal. 



The genus Hexalonchidium exhibits the same relation to Hexalonche that Hexa- 

 stylidium bears to Hexastylus ; the growth of the three spine-paii-s is different, whilst 

 both spines of each pair are equal ; they correspond therefore to the three axes of a 

 rhombic crystal. 



1. Hexalonchidium axonometrum, n. sp. 



Cortical shell thin walled, covered with short bristle-shaped by-spines, twice as broad as the 

 medullary shell ; both with regular hexagonal meshes, twice to three times as broad as the bars (inner 

 meshes half as broad as the outer). All three spine-pairs three-sided prismatic, of very different 

 length but of equal breadth (equal to three pores). Major spine-pair twice as long as the shell 

 diameter ; middle pair about equal to the latter, minor scarcely half as long. (Similar to Hexalonche 

 anaximandri, PI. 22, fig. 5, but distinct in the different length of the spines.) 



Dimensions. — Diameter of the outer shell 012, inner 0-06 ; length of the major spines 0'25, 

 middle O'l, minor 0'04. 



Hahitat. — Indian Ocean, Madagascar, surface, Eabbe. 



Subfamily Hexacontida," Haeckel, 1881, Prodromus, pp. 449, 452. 



Definition. — C ubosphserida with three concentric, spherical, or octahedral 

 lattice-shells. 



^ Hexalonchidium = Q\ie\\ with six spears; derivation from Hexalonche. 

 2 Hexacontida = Cutosphierida triplicia = Triosphteri da liexacaiitlia. 



