798 THE VOYAGE OF H.M.S. CHALLENGEE. 



1. Sphcerocapsa cmciato, n. sp. (PL 135, figs. 6, 7). 



Aspiiial holes nearly circular, with flat radially striated margin. Four aspinal pores of each 

 hole rounded equilateral triangular. Porules of the shell simple, without ring and diinple. Four 

 edges of the spines smooth. 



Dimensions. — Diameter of the shell 0'4 to 0-5, of the central capsule 0'3 to 0'4. 



Habitat. — North Atlantic, Fasroe Channel (Gulf Stream), 1880, John Murray, surface. 



2. Sphcerocapsa dentata, n. sp. (PL 135, fig. 9). 



Aspinal holes four-lobed, with broad concave margin denticulated on the periphery. Foui- 

 aspinal pores of each hole pear-shaped, oblong, elevated in the centre. Porules of the shell simple, 

 without ring and dimple. Four edges of the spines denticulate. 



Dimensions. — Diameter of the shell 0'3 to 0'4, of the central capsule 0"2 to 0".3. 



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



3. Sphcerocapsa quadrata, n. sp. (PL 135, fig. 8). 



Aspinal holes square, with concave umbilicus in the centre, surrounded by a convex 

 denticulated margin. Four aspinal pores of each hole nearly square. SheU-porules with a polygonal 

 elevated smooth ring, in the bottom of a shallow dimple. Four edges of the spines smooth. 



Dimensions. — Diameter of the shell 0"22, of the central capsule 0'17. 



Habitat. — Indian Ocean, soutli of Australia, Station 159, surface. 



4. Sphcerocapsa p>avimentata, n. sp. (PL 135, fig. 10). 



Aspuial holes four-lobed, with Inroad concave, irregularly crenated and figured margin. Four 

 aspinal pores of each hole vioUn-shaped. Porides of the shell surrounded by an irregularly oblong 

 ring with thick elevated, elegantly crenated margin. Four edges of the spines smooth. 



Dimensions. — Diameter of the shell 0'3(;>, of the central capsule 0*3. 



Habitat. — South-east Pacific (off Valparaiso), Station 298, surface. 



Genus 345. Astrocapsa,^ u. geu. 



Definitivn. — S phjerocapsida with twenty radial spiues longer than the radius 

 of the shell, piercing its perspinal holes, with free external prolongation ; therefore 

 with four aspinal pores around each spine. 



The genus Astrocapsa diflers from the preceding Spluerocapsa in the exteinal 

 prolongation of the radial spines piercing the perspinal holes ; it assumes therefore the 

 common shape of the Dorataspida more than the other Sphserocapsida .do.. 



1 .4strocoj3sa = Star-capsule ; eiur^au, r.i:i,a. 



