Yol.  49.]  FROM  THE  DISTRICT  OF  GIRVAH,  AYRSHIRE.  297 
Size. — Eig.  1  :  Length  -56,  height  -44  millim. 
Pig.  2  :  Length  *76,  height  *48  millim. 
Eig.  3  :  Length  1*16,  height  *76  millim. 
These  small  Ostracods,  having  the  outline  of  a  Leperditia  without 
any  of  its  other  features,  come  within  the  group  of  Aparchites. 
A.  Maccoyii  (Salter),1  from  the  Lower-Silurian  limestone  of  the 
Chair  of  Kildare,  Ireland,  and  known  also  from  Aldens,  on  the 
Stinchar  Kiver,  in  Ayrshire,2  approximates  to  fig.  1  in  shape,  but  is 
much  larger  and  more  oval. 
The  smaller  Aparchites  mutus ,3  J.  &  H.,  with  rounded  and  nearly 
equal  ends,  from  the  Upper  Silurian  of  Beechey  Island,  is  also  a 
close  ally.  Two  little  4  Primitice  ’  from  the  Olenus- shales  of 
Shineton  4  are  also  Aparchites ,  nearly  allied  to  fig.  1 ;  but  one  of 
them  is  too  attenuate,  and  the  other  too  oblong. 
Our  Girvan  specimen,  fig.  1,  is  more  ovate  than  A.  matutinus , 
•Tones  &  Holl,5  from  the  Bala-Caradoc  formation  at  the  Biver  Onny, 
near  Chenev-Longville,  Shropshire  ;  and  more  oblong  than  A.  semi- 
circularis ,  J.  &  H.,6  from  the  Scandinavian  limestone  of  the  North- 
German  Drift. 
Eig.  2  is  larger  and  more  oblong  than  fig.  1,  having  its  antero- 
ventral  region  developed  with  a  bolder  curve  ;  thus  almost,  but  not 
quite,  identifying  itself  with  A.  matutinus ,  J.  &  H. 
Eig.  3  is  almost  oblong,  except  that  its  ventral  region  is  curved 
and  not  straight.  Its  extremities  are  nearly  equally  rounded  ;  and 
its  long,  straight,  dorsal  edge  ends  with  pronounced  angles. 
These  three  specimens  are  evidently  gradations  of  one  form,  and 
the  other  figures  above  mentioned  supply  some  intirmediate  shapes. 
In  a  grey  shale,7  nos.  116  (fig.  1),  123  (fig.  2),  115  (fig.  3). 
2.  Aparchites  stjbovattjs,  Jones.  See  the  preceding  paper,  p.  292, 
PI.  xii.  figs.  7-9.  (PI.  XIII.  figs.  4  &  5.) 
Size. — Eig.  4  :  Length  1*0,  height  ’52  millim. 
Eig.  5  :  Length  1*48,  height  *68,  thickness  *4  millim. 
In  the  Quart.  Journ.  Geol.  Soc.  vol.  xlvi.  1890,  pp.  7-9,  pi.  iii. 
figs.  18,  19,  21-23,  some  long-ovate,  variable  forms,  having 
Primitian  features  to  some  extent,  but  in  many  instances  destitute 
of  the  characteristic  sulcus,  were  described  and  figured,  and  some 
synonyms  were  mentioned  and  discussed.  Primitia  concinna ,  Jones, 
with  its  prior  name  P.  minuta  (Eichwald),  was  accepted,  because 
1  Ann.  Mag.  Nat.  Hist.  ser.  4,  vol.  ii.  1868,  p.  55,  pi.  vii.  figs.  1-3  (Primitia). 
2  Ibid.  p.  56.  It  also  occurs  in  the  Lower-Silurian  Beyrichien-Kalk  of  the 
North-German  Drift.  Krause,  Zeitschr.  Deutsch.  geol.  Gesellsch.  vol.  xliii. 
1891,  p.  494,  pi.  xxx.  fig.  3. 
3  Ann.  Mag.  Nat.  Hist.  ser.  3,  vol.  i.  1858,  p.  254,  pi.  ix.  fig.  3  a  ( X  4),  3  b 
( X  24),  then  termed  ‘  Cytheropsis  concinna  ?  ;  ’  and  ibid.  ser.  3,  vol.  xvi.  1865, 
p.  425  ( Primitia  muia). 
4  Ibid.  ser.  4,  vol.  iii.  1869,  p.  221,  (woodcuts)  figs.  6  and  7. 
5  Ibid.  ser.  3,  vol.  xvi.  1865,  p.  418,  pi.  xiii.  fig.  7,  then  regarded  as  a  Primitia. 
6  Ibid.  p.  424,  pi.  xiii.  fig.  10  {Primitia). 
7  This  dark-grey  shale  from  Whitehouse  Bay  is  very  full  of  Ostracodous 
valves  and  other  small  fossils. 
Q.J.G.  S.  No.  195. 
x 
