REPORT ON THE RADIOLAR1A. 1613 



work partly pierced by a hole. The peculiar network of a complete specimen, observed by me at 

 Portofino in 1880, was so similar to that of Spongodictyon trigonizon, described above (p. 91), and 

 figured in 1862 in my Monograph, that I am doubtful if the two forms are not identical, the two 

 medullary shells of the latter being accidentally entangled in the framework. (Compare p. 1602.) 



Dimensions. Diameter of the sphere I'l to 1*5, length of the bars 01 to 0'2, breadth 0'002. 



Habitat. Mediterranean (Messina, Portofino), surface. 



Genus 680. Sagmidium, 1 n. gen. 



Definition. S ago sphserida with a spongy spherical shell, the thickened wall of 

 which is composed of a loose spongy framework, and bears on the nodal points of its 

 surface radial spines. 



The genus Sagmidium differs from the preceding Sagmarium in the development 

 of radial spines on the surface of the spongy hollow sphere. It bears therefore the same 

 relation to the latter as Sagosphcera does to Sagena, and may be derived either from 

 Sagmarium by the formation of radial spines, or from Sagosphcsra by development of 

 the spongy envelope. 



1. Sagmidium unicorne, n. sp. 



Eadial spines simple, straight, smooth, a single one at each nodal point of the surface of the 

 spongy sphere, bearing on its distal end a spinulate knob, or a bunch of numerous radial bristles. 

 (Similar to Sayenoscena pcnicillata, PI. 108, fig. 10.) Bars of the spongy framework smooth. 



Dimensions. Diameter of the sphere 3'0 to 3'5, length of the bars 0'15 to 0'2, breadth O'OOS 

 to 0-006. 



Habitat. Antarctic Ocean, Station 256, surface. 



2. Sagmidium income, n. sp. 



Eadial spines simple, smooth, usually three divergent united at each nodal point of the surface 

 (sometimes two or four instead of three). Each spine bears on its distal end three short divergent 

 conical teeth. (Similar to the terminal teeth of Sagoscena tentorium, PI. 108, fig. 6.) Bars of the 

 spongy framework smooth. 



Dimensions. Diameter of the sphere l - 6 to 24, length of the bars 0'06 to Q-09, breadth O'OOl 

 to 0-002. 



Habitat, Central Pacific, Stations 263 to 268, surface. 



3. Sagmidium crucicorne, n. sp. (PI. 108, fig. 9). 



Eadial spines slender, verticillate, three or four divergent arising from each nodal point of the 

 surface. Each spine bears three to six cruciate verticils of lateral branches ; each verticil being 



1 Sagmidium = Small armour, military cloak ; <?//* ftion. 



