REPORT ON THE RADIOLARIA. 1165 



and the other eighteen tertiary. Between them very numerous peripheral beams. Margin broad 

 horizontal, reflexed like the brim of a " Bismarck " hat. 



Dimensions. Shell 0'17 long, 0'38 broad. 



Habitat. South Pacific, Station 298, depth 2225 fathoms. 







Genus 515. Cladarachnium, 1 Haeckel, 1881, Prodromus, p. 430. 



Definition. A rchiphormida (vel Monocyrtida multiradiata aperta) with flatly 

 conical, tent-shaped or nearly discoidal shell, and numerous branched radial beams. 



The genus Cladarachnium differs from the preceding Litharachnium only in the 

 ramification of the radial beams, the distal' ends of which project over the margin of the 

 shell. Only one species of the genus has been observed. 



1. Cladarachnium ramosum, n.. sp. (PI. 55, figs. 5, 6). 



Shell flatly conical or tent-shaped, with nearly straight lateral outlines; apical part somewhat 

 higher. Apex with three cortinar pores, surrounded by a few girdles of larger pores. From these 

 there arise about twelve to fifteen strong radial beams at unequal' distances; these are somewhat 

 curved and irregularly branched. The network between them has irregular polygonal meshes and is 

 more delicate towards the periphery. Margin with twenty-four to thirty irregular indentations or 

 concave excisions, separated by the prominent distal ends of the branched ribs. 



Dimensions. Shell 4 16 long, 0'4 broad. 



Habitat. Central Pacific, Station. 271, surface.. 



Genus 516. CyrfopHormis, 2 n. gen. 



Definition. A rchiphormida (vel Monocyrtida multiradiata aperta) with ovate 

 or urceolate shell and numerous radial ribs in its wall. Mouth more or less con- 

 stricted, smooth, truncated. Apex without horn. 



The genus Cyrtophormis, like the preceding genera, exhibits numerous prominent 

 radial or longitudinal ribs in the wall of the urceolate shell ; it differs from these in 

 the constricted and truncated mouth, with smooth margin of the peristome. 



1. Cyrtophormis pila, n. sp. (PI. 52, fig. 1). 



Shell balloon-shaped, subspherical, with twenty denticulate meridional ribs, alternating with 

 twenty longitudinal rows of circular pores, which are twice as broad as the bars. Peristome con- 

 stricted and then dilated, smooth, half as broad as the shell. 



Dimensions. Shell Oil long, 0'09 broad; mouth 0'06 broad. 



Habitat. Central Pacific, Station 268, depth 2900 fathoms. 



1 Cladarachnium = Spider-web with branched threads ; 



2 Cyrtophormis = Fishing- basket ; 



