272 THE VOYAGE OF H.M.S. CHALLENGER. 



Dimensions.— Dinmeter of the sjjhere 0'16 ; length of the main spines Oil, of the by- 

 spines O'Oo. 



Habitat. — Fossil in the Alpine Jura, Schafberg near Salzburg (Dunilcowski). 



7. Spongiomma asteroides, n. s^i. 



Spongy fi-amework in the central part of the sphere much denser and darker than 

 in the peripheral part. Sixty to eighty cylindro-conical main spines, as long as the radius, 

 between them are nmuerous straight, bristle-shaped by-spines half that length. 



Dimensions. — Diameter of the sphere 0-28 ; length of the main spines 0-16, of the by- 

 spines 0'08. 



Habitat. — South Atlantic, Station 325, surface. 



Genus 112. Spongodrt/mus,^ Haeckel, 1881, Prodromu.s, p. 456. 



Definition. — As t ro s pli se r id a with solid spongy sphere, without hitticed 

 meduUary shell, with numerous branched radial spines. 



The genus Spongodrymus differs from the preceding Spongiomma in the ramifica- 

 tion of the numerous radial spines, covering the surface of the solid spongy sphere. 



1. Spongodrymus elaphococcus, n. sp. (PI. 18, fig. 9). 



Spongy framework of the solids phere equal throughout, on the surface arising in the form of 

 very numerous (sixty to eighty or more) spongy cones with rather rhomboidal meshes. Each cone is 

 prolonged into a very thin, irregularly curved radial spine, which is twice as long as the shell 

 diameter, simple in the proximal half, branched like a tree in the distal half ; each arborescent spine 

 has from sixteen to thirty-two terminal branches, which fall in one spherical face. The branches of 

 neighbouring spines are partly connected by anastomoses, so that they begin to form an outer 

 spherical shell (cortical shell) with a looser spongy framework. 



Dimensions. — Diameter of the whole spherical skeleton (sphere formed liy the distal ends of the 

 dichotomous branches) 0-9, of the inner solid spongy sphere 0-02. 



Habitat. — Tropical Atlantic, Station 349, surface. 



2. Spongodryniu.^ ahietinus, n. sp. 



Spongy framework denser and darker in tlie central jiart of the sphere than in the peripheral 

 part, with rather coarse meshes and thick bars. From the surface arise very numerous (sixty to 

 eighty) stout, radial branches, as long as the shell radius, branched like a pine tree (with six to 

 twelve ramified branches). Similar in structure to Cromyodrymus abietimis (PI. 30, fig. 6), but witli 

 a quite irregular spongy texture in the central sphere. 



Dimensions. — Diameter of the sphere 0'3 ; length of the spines 0'015. 



Habitat. — Central Pacific, Station 272, surface. 



' Spongodrymus = Spongy wood ; avioyyo;, a/aifios. 



