152 



THE VOYAGE OF H.M.S. CHALLENGER. 



L Subfamily 



StaurostyliJa. 

 (Shell one single lattice-sphere. ) 



Synopsis of the Genera of StaurosplicBi'ida. 



All four sjjiues equal, 



Four spine.? different in pairs, 



II. Subfamily 



Stauroloncliida. 

 (Shell with two concentric lattice-spheres. 



III. Subfamily 



Stauracontida. 

 (Shell with three concentric spheres.) 



IV. Subfamily 



Staurocromyida. 

 (Shell with four concentric spheres. ) 



V. Subfamily 



StaurooaryiJa. 



One spine larger than the tbree 

 others, ..... 



. T, J ■ ( Simple. 



Ail tour spines I ^ ' 



equal, 



Branched, . 



] Four spines differeut in pair.s, 



One spine larger than the three 

 others, ..... 



All four spines equal, simple, 



I All four .spines J ' ^ ' 

 f "'l'"'' ( Branehed, 



I 



(Shell with five or more concentric spheres.) J 



All four spines equal. 



VI. Subfamily 



Staurodorida. 



(Shell a spongy sphere. ) 



( Solid sponpty sphere without medul- 

 ( lary shell, ..... 



60. Staurosphrera. 



61. Sfanrosti/Ius. 



62. Stylostaurug. 



63. Staurolonchi'. 



64. Staarancistra. 



65. Staurolonclddiu-in. 



66. Stawoxiphos. 



67. Staaracontiinti. 



68. Staurocromyum. 



69. Gromijostaunis. 



70. Staurocarijiim. 



71. Staurodoras. 



Subfamily Staurostylida,^ Haeckel, Prodromus, 1881, pp. 449, 450. 

 Definition. — S t a u r o s p li se r i d a with one single spherical lattice-sheU. 



Genus 60. Stau7'0sphcera,^ Haeckel, 1881, Prodromus, p. 450. 



Definition. — S t aur osp hajr i da with a single lattice -sphere and four crossed 

 equal spines. 



The genus Staurosphcera maybe regarded as the common ancestral form of this sub- 

 family, since it represents their most simple and primitive form. From the surface 

 of the simple lattice-sphere, enclosing the central capsule, arise four ec^ual, simple, radial 

 spines, opposite in pairs in two diameters, perpendicular one to another. Staurosphcera 

 may be derived phylogenetically either from Cenosphcera by production of the four 

 spines, or from Hexastylus by reduction of two opposite spines. 



1 Staurostylida = Staurosphoerida simplieia = Monosi^bKi-ida tetracantha. 

 - Staiiro.sp/tara = Cross-.sphere ; uTav^i;, i!(paioa. 



