REPORT ON THE RADIOLARIA. 1627 



20. Aulosphcera undulata, n. sp. (PL 109, fig. 6). 



Eadial tubes slender, cylindro-conical, undulate, about twice as long as the spinulate and 

 undulate tangential tubes; studded with numerous short, perpendicular, lateral branches which are 

 partly simple, partly forked, and bear small terminal spathillse. The distal end of each radial tube 

 bears usually a verticil of four to eight similar pediculate spathillae. 



Dimensions. Diameter of the sphere 2'4; tangential tubes 0'2 long, 0'005 broad. 



Habitat. North Pacific, Station 252, surface. 

 / 



21. Aulosphcera spinosa, n. sp. (PI. 109, fig. 5). 



Eadial tubes and tangential tubes equal in size and similar in form, more or less curved, slender, 

 cylindrical, densely studded with numerous irregular spines. 



Dimensions. --Diameter of the sphere l - 6 ; tangential tubes O'l long, 0'004 broad. 

 Habitat. Central Pacific, Station 271, depth 2425 fathoms. 



Genus 684. Auloscena, 1 n. gen. 



Definition. A ulosphserida with triangular meshes in the network, the tangential 

 tubes of which arise in pyramidal groups of six over the surface of the spherical shell. 

 Radial tubes arise at the tops of the six-sided pyramids, which cover the whole 

 surface. 



The genus Auloscena differs from the preceding Aulosphara, its ancestral form, in 

 a very remarkable and elegant character. The tangential tubes of the network here lie 

 not on a spherical face (as in the latter), but arise over the surface of the spherical 

 calymma in the form of numerous, regular, hexagonal pyramids ; each pyramid being com- 

 posed of six convergent ascending tubes, which are united in a common nodal point; at 

 the latter arises a radial tube, which usually bears an elegant corona of radially divergent 

 terminal branches. Therefore the base of each hexagonal pyramid is in contact at its 

 six corners with the basal corners of six similar neighbouring pyramids, whilst the 

 neighbouring sides of the bases are separated by six regular triangular meshes, which 

 lie on the spherical face. In some species this remarkable and elegant structure is 

 quite regular, whilst in others it becomes more or less irregular. 



Subgenus 1. Auloscenium, Haeckel. 



Definition. Radial tubes smooth, without lateral branches or spines, bearing a 

 terminal verticil at the distal end. 



1 Aulascma = Tubular tent ; .v*.i;, <rxii. 



