224  DR.  G-.  J.  HINDE  ON  A  RADIOLARIAN  ROCK  FROM  [May  1 893, 
Amphibrachium,  sp.  (PI.  V.  fig.  13.) 
Test  elongate,  biclavate,  with  a  sub-circular  central  disc  ;  the 
arms  have  rounded  ends  and  are  divided  by  five  or  six  curved  par¬ 
titions.  Surface  characters  are  not  shown.  Length,  *265  mm.; 
thickness  near  end  of  arms,  -060  mm.,  in  the  centre,  *040  mm.  Rare. 
Spongodiscus  expansus ,  n.  sp.  (PI.  Y.  fig.  6.) 
Test  sub-circular  in  outline,  with  an  apparently  minutely  reticu¬ 
late  or  porous  structure  throughout.  There  is  no  differentiation 
shown  in  the  central  area.  Diameter  of  the  test,  *28  mm.  Not 
uncommon. 
Spongodiscus,  sp.  (PI.  V.  fig.  7.) 
Test  circular,  the  structure  minutely  reticulate,  as  in  the  preceding, 
but  there  are  traces  of  a  medullary  test.  Diameter  of  the  test, 
•18  to  *20  mm. ;  of  the  central  area,  *05  mm.  Not  uncommon. 
Spongodiscus ,  sp.  (PI.  Y.  fig.  2.) 
Test  oval,  with  a  marginal  border  of  small  triangular  spines. 
The  surface  is  very  imperfectly  shown  ;  it  appears  to  be  minutely 
reticulate.  Diameter,  *14  mm. ;  breadth,  *11  mm.  Rare. 
Spongolcna  symmetrica ,  n.  sp.  (PL  Y.  fig.  12.) 
Test  in  form  like  a  dumb-bell ;  the  ends  of  the  arms  are  inflated 
and  rounded,  while  the  central  portion  is  nearly  cylindrical.  Structure 
minutely  reticulate.  Length,  from  -210  to  -345  mm. ;  breadth  of  the 
ends,  -055  to  -070  mm. ;  of  the  central  portion,  -035  mm.  Common. 
Sub-order  Cyrtoidea,  Haeckel. 
Dictyomitra  australis ,  n.  sp.  (PI.  Y.  fig.  14.) 
Test  conical,  gradually  increasing  in  width  to  the  base,  with  from 
eight  to  ten,  nearly  horizontal,  transverse  partitions  or  constrictions, 
marking  off  as  many  segments.  In  the  sections  only  the  outlines 
and  the  partitions  can  be  seen.  Length,  *27  mm. ;  width  at  base, 
•13  mm.  This  form  is  somewhat  larger  and  wider  at  the  base  than 
Dictyomitra  ( Litliocampe )  cretcicea,  Riist  (‘  Palseontographica,’  vol. 
xxxi.  p.  313,  pi.  xxxix.  fig.  3,  and  vol.  xxxviii.  p.  187)  from  the 
Lower  Devonian  in  the  Southern  Ural,  and  from  different  horizons 
of  the  Cretaceous  in  Italy  and  Switzerland. 
Dictyomitra  triangularis ,  n.  sp.  (PI.  Y.  fig.  15.) 
Shell  conical,  gradually  increasing  in  width  to  the  base,  with 
from  seven  to  eight  horizontal  partitions.  Length,  *19  mm. ;  width 
at  base,  *10  mm.  The  surface-pores  are  faintly  shown  in  places. 
Rare. 
