208 



THE VOYAGE OF H.M.S. CHALLENGER. 



I. Subfamily 



Coscinommida. 

 (One single latticed shell.) 



Synopsis of the Genera of Astrosphcerida. 



( All spines of the same 

 j kind, .... 



Larger main spines and 

 smaller by-spines, 



Spines all simple, not 

 branched and not tubu- 

 lous. 



Spines hollow conical tubes with porous walls, 



Between simple spines the pores prolonged in hollow 

 tubes, ...... . 



Spines branched or forked 



f Spines with 

 branches, 



lateral 



I Spi 



nes forked or dichoto- 



mous, 



IT. Subfamily 



Haliommida. 

 (Two concentric latticed 

 shells.) 



A. Elatommida,onemedul- 

 lary and one cortical -j 

 shell. 



B. Diplosphaerida, both 

 shells cortical. 



All spines equal, simple, . 



All spines simple, of two 

 different kinds, 



[ Spines branched, 

 No by-spines, . 

 Inner by-spines, 



III. Subfamily 



Actinommida. 

 (Three concentric latticed 

 shells. ) 



IV. Subfamily 



Cromyommida. 

 (Four concentric latticed 

 shells.) 



V. Subfamily 



Caryommiila. 

 (Numerous, five to ten or 

 more, concentric latticed 

 shells. ) 



Outer by-spines, 



Outer and inner by-spines, 



( All spines equal, 



Eadial spines not branched J Larger main gpineg and 



[ smaller by-spines, 



[ Radial spines branched or forked, 



fAll spines equal, 

 Larger main spines and 

 smaller by-spines, 



Radial spines branched or forked, 



Two medullary shells and three or more cortical shells 

 (lattice work ordinary), ... 



Triangular meshes, simple 

 bars, without diagonal 



No medullary shells (lattice 



work arachnoidal); three- Tri lar mes hes, simpL 



sided prismatic spines, -j 1io ^. ,,;! ii, 



with verticils of three 



forked branches. 

 (Arachnosphaerida.) 



bars; diagonal bars 

 between the shells, 



Polygonal meshes, bars 

 branched, . 



88. Acanthosphcera. 



89. Heliosplmra. 



90. Gonosphcera. 



91. Coscinomma. 



92. Cladococcus. 



93. Elaphococcus. 



94. Haliomma. 



95. Heliosoma. 



96. Elatomma. 



97. Leptosphcera. 



98. Diplosphtera. 



99. Drymospliasra. 



100. Astrosphcei-a. 



101. Aetinomma. 



102. Ecliinomma. 



103. Pityomma. 



104. Cromyomma. 



105. CromyecMnus. 



106. Cromyodrymus. 



107. Caryomma. 



108. Arachnopila. 



109. Araclinopeyma. 



110. A rachnosphcera. 



