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



Subgenus 4. Staurosph(Bromma, Haeckel. 



Definition. — Pores irregular, of different size or form ; surface covered with by-spines 

 or accessory thorns. 



14. StaurosphcBra hartholomcBi, n. sp. 



Shell thin wahed, with irregular, polygonal pores, three times as broad as the bars ; six to eight 

 on the quadrant ; surface covered with short bristle-shaped by-spines. Four main spines three-sided 

 pyramidal, twice as long as the radius. 



Dimensions. — Diameter of the shell 014, pores O'OOS to 0-016, bars 0-003 to 0-005. 



Habitat. — South Pacific, Station 285, depth 2375 fathoms. 



15. StaurosphcEra thaddcei, n. sp. 



Shell thick walled, with irregular, roundish, polygonally framed pores, twice to three times as 

 broad as the bars ; five to seven on the quadrant ; surface covered with bristle-shaped spines, half 

 as long as the radius. Four main spines pjTamidal, as long as the radius. 



Dimensions. — Diameter of the shell 0-12, pores 006 to 0012, bars 0-004. 



Habitat. — Central Pacific, Station 266, depth 2750 fathoms ; also fossil in Barbados. 



16. Staurosph(B}xi matthcei, n. sp. 



Shell thick walled, with irregiilar, roundish pores, twice to five times as broad as the bars ; ten to 

 twelve on the quadrant ; surface covered with short conical thorns or by-spines. Four main spines 

 conical, as long as the radius. 



Dimensions — Diameter of the shell O'lS, pores 0-004 to 0-01, bars 0-002. 



Habitat. — North Pacific, Station 253, depth 3125 fathoms. 



Genus 61. Staurostylus,^ Haeckel, 1881, Prodromus, p. 450. 



Definition. — S t au r o sphjer ida -^dth one single lattice-sphere and four crossed 

 spines which are arranged in opposite pairs, one pair opposite being larger than the other. 



The genus Staurostylus has been developed from Staurosphcera by differentiation of 

 the four crossed spines in pairs ; tw^o opposite spines growing much more strongly than 

 the other two. 



1. Staurostylus grcBciis, n. sp. 



Shell thick walled, smooth, with regular, circular, hexagonaUy framed pores, twice as broad as 

 the bars ; six to eight on the quadrant. Spines three-sided prismatic, pointed, as broad as 



1 Staurosty Ills = CTOSS-sty\e ; aTetvo6(,ar'i'Ko;. 



