REPORT ON THE RADIOLARIA. 1633 



species resembles in its simple slructure the common cosmopolitan Aidusphccra triijonopa, and diflers 

 from it only in the constant spindle-form of the shell. 



Dimensions. — Length of the shell G to 8, breadth 3 to 4 ; length of the radial tubes 0'16 to 0'2, 

 breadth 0-008. 



Hahitat. — Xorth Atlantic, F;eroe Channel, Gulf Stream (Jolm ]\Iurray) ; Hebrides (iloebius). 



4. Aulatractus dlipsoides, n. sp. 



Shell ellipsoidal, about twice as long as broad, with equally rounded poles on the main axis. 

 Eadial tubes straight, cylindrical, verticillate, about twice as long as the smooth tangential bars ; 

 each verticil is cruciate, composed of four rectangularly crossed, short, lateral branches which bear a 

 small spathilla at the distal end. 



Dimensions. — Length of the shell 6'6, breadth 3'6 ; length of the radial tubes 0'2, breadth O'OL 



Habitat. — South Atlantic, Station 332, surface. 



Subfamily 2. Aulonida, Haeckel. 



Definition. — Network of the shell with polygonal, usually irregular meshes ; three 

 or four tangential tubes usually being united at each nodal point. 



Genus 688. Aulonia,^ n. gen. 



Definition. — Aul o sph eer id a with polygonal meshes in the network, the 

 tangential tubes of which form a simple smooth lattice-sphere. No radial tubes at the 

 nodal points. 



The genus Aulonia is the simplest form of the subfamily Aulonida, or of those 

 Aulosphserida in which the lattice-work of the shell is composed not of triangular but 

 of polygonal meshes ; all these Aulonida are much rarer and much less differentiated 

 than the Aularida or the common Aulosphrerida with triangular meshes. Aulonia has 

 the same .simple, smooth, spherical lattice-shell as Aularia, and difiers from it only in 

 the polygonal form of the meshes, which, however, is very constant. 



1. Aulonia tetragonia, n. sp. 



Meshes regular or subregular, square, sometimes intermingled with a variable number of irregular, 

 triangular, and pentagonal meshes. Bars cylindrical, of equal breadth. 



Dimensions. — Diameter of the .spherical shell 2'0 to 3'2, of the meshes 012 to 018 ; breadth of 

 the bars 0-008. 



Hahitat. — Antarctic Ocean, Station 154, depth 1800 fathoms. 



' >4MZonm= Tubular object; au'hoc, utlon. 



(ZOOL. CHALL. EXP.— PART XL. — 1886.) Rr 205 



