.REPORT ON THE RADIOLARIA. 875 



1. Hexalaspis heliodiscus, n. sp. (PL 139, fig. 2). 



All six hydrotomical spines of nearly equal size (or sometimes the two equatorial a little larger 

 than the four polar spines), isosceles triangular, compressed, smooth ; about as long as the radius of the 

 shell, and half as broad at the base. The fourteen other spines very small, also triangular and 

 compressed, but little prominent on the two convex sides of the lenticular shell. 



Dimensions. Diameter of the shell O'll ; length of the six hydrotomical spines O'Oo, basal 

 breadth O03. 



Habitat. Central Pacific, Station 271 to 274, surface. 



2. Hexalaspis stellata, n. sp. 



All six hydrotomical spines of nearly equal size, lanceolate compressed, with two longitudinal 

 furrows on each flat side, about as long as the diameter of the shell, and one-fourth as broad at the 

 base. The fourteen other spines very thin, also compressed, half as long and only one-fourth as 

 broad as the six large spines. 



Dimensions. Diameter of the shell 0'14 ; length .of the six hydrotomical spines 0'13, basal 

 breadth 0'035. 



Habitat. South Pacific, Station 284, surface. 



Subgenus 2. Hexalaspidium, Haeckel. 



Definition. Six hydrotomical spines of unequal size, two opposite (equatorial) much 

 larger than the four other (polar) spines. 



3. Hexalaspis sexalata, n. sp. 



Six hydrotomical spines of unequal size ; the two equatorial spines about as long as the shell- 

 radius and twice as long as the four polar spines, which are isosceles triangular. The fourteen other 

 spines are only half as long and one-fourth as broad as the latter, little prominent. (Resembles 

 Hexonaspis hastata, PL 140, fig. 16, which is distinguishable by the furrows on the six spines and 

 by the total absence of the fourteen external rudimentary spines.) 



Dimensions. Diameter of the shell 015 ; length of the two equatorial spines 0'08, of the four 

 polar spines 0'04, of the fourteen other spines - 02. 



Habitat. North Pacific, Station 240, surface. 



4. Hexalaspis hexalastrum, n. sp. 



Six hydrotomical spines of unequal size ; the two equatorial spines somewhat longer than the 

 diameter of the shell and three times as long as the four polar spines, all six triangular, smooth, of 

 the same basal breadth (equal to half the radius). The fourteen other spines very thin, conical at 

 the base, nearly as long as the radius. 



