Vol.  49.]  FANNY  BAY,  PORT  DARWIN,  AUSTRALIA.  223 
these  radiolaria  it  is  not  practicable  at  present  to  determine  the 
geological  horizon  of  the  rock  ;  with  one  exception,  all  the  genera 
represented  occur  from  Palaeozoic  times  to  the  present. 
Class  Badiolaria,  Muller. 
Sub-order  Prunoidea,  Haeckel. 
Cenellipsis ,  sp.  (PI.  Y.  fig.  1.) 
Test  regularly  oval  in  outline ;  *160  mm.  in  length,  by  *115  mm. 
in  breadth.  Occasional  traces  of  circular  pores,  about  #011  mm.  in 
breadth.  Oval  tests  of  this  character  are  by  no  means  uncommon 
in  the  deposit,  but  it  is  seldom  that  pores  are  shown. 
Sub-order  Discoidea,  Haeckel. 
Astrophacus ,  sp.  a.  (PI.  Y.  figs.  4,  5.) 
Tests  nearly  circular  in  outline,  with  two  medullary  tests  con¬ 
nected  by  rays,  and  numerous  small,  subequal,  marginal  spines  ;  in 
fig.  4  the  spines  are  only  partially  preserved.  Diameter  of  test,  from 
•13  to  *16  mm. ;  of  the  outer  medullary  test,  *06  to  *07  mm. ;  and  of 
the  inner,  *02  mm.  The  pores  in  the  test  are  not  shown.  Bare. 
Astrophacus,  sp.  b.  (PI.  Y.  fig.  3.) 
Test  regularly  oval  in  outline ;  *13  mm.  in  length,  by  °10  mm.  in 
breadth ;  the  outer  and  inner  medullary  tests  are  *06  and  *03  mm. 
in  diameter.  There  is  a  border  of  small  spines.  Bare. 
Lithocydia  eccilis ,  n.  sp.  (PI.  Y.  fig.8.) 
Test  circular  in  outline,  with  from  6  to  8  rings  surrounding  the 
medullary  sphere.  Diameter  of  test,  *150  mm. ;  of  the  central  sphere, 
about  *028  mm. ;  distance  between  the  rings,  -010  mm.  The  surface- 
pores  of  the  test  are  faintly  shown.  Hot  uncommon. 
Amphibradiium  crassum ,  n.  sp.  (PI.  Y.  fig.  9.) 
Test  elongate,  with  the  ends  slightly  inflated  and  rounded. 
Structure  of  minute  pores  irregularly  disposed.  Length,  °245  mm. ; 
breadth,  *041  mm.  Hot  uncommon. 
Annpliibradiium  trunccitum,  n.  sp.  (PL  Y.  fig.  10.) 
Test  elongate,  biclavate ;  the  arms  either  truncate  or  slightly 
furcate  at  the  ends.  Structure  of  minute  pores.  Length,  *21  mm. ; 
thickness  at  the  ends,  *05  mm. ;  in  the  centre,  *03  mm.  Bare. 
Amphibrachium  fragile,  n.  sp.  (PI.  Y.  fig.  11.) 
Test  biclavate,  with  a  slight  inflation  in  the  centre.  Structure 
of  minute  pores,  partly  arranged  in  longitudinal  series.  Length, 
•245  mm. ;  thickness  at  the  ends,  *050  mm. ;  in  the  centre,  *030  mm. 
Bare. 
