288 
PROF.  T.  R.  JONES  ON  SOME  PALAEOZOIC  [Aug.  1 893, 
24.  On  some  Paleozoic  Ostracoda  from  Westmoreland.  By  Prof. 
T.  Rupert  Jones,  F.R.S.,  F.G.S.  (Read  April  12th,  1893.) 
[Plate  XII.1 2 3 4 5] 
Contents. 
Page 
§  1.  Introduction  .  288 
§  2.  References  to  Figures  and  Descriptions  of  Groups  of  mutually- 
relaied  Ostracoda  of  Palaeozoic  Age  .  288 
§3.  References  to  former  Notes  on  the  Lower-Palaeozoic  Ostracoda  of 
the  Lake  District  .  289 
§  4.  Table  of  the  Formations  referred  to  .  290 
1 5.  Description  of  the  Species  and  Varieties .  291 
§  6.  List  of  Species  of  Lower-Palaeozoic  Ostracoda  from  the  Lake 
District  .  295 
§  1.  Introduction. 
In  1865  the  Author  determined  for  Prof.  Harkness  some  fossil 
Ostracoda  which  he  had  obtained  from  the  Lower-Silurian  rocks  of 
S.E.  Cumberland  and  N.E.  Westmoreland,  and  subsequently  other 
specimens  mentioned  by  Harkness  and  Nicholson  in  1872.  In 
1891  Prof.  Nicholson  and  Mr.  Marr  submitted  a  series  of  similar 
microzoa  from  the  same  district ;  and  the  Author  now  endeavours 
to  determine  their  specific  alliances,  and  revises  the  list  of  those 
previously  collected.  He  has  to  notice  about  eleven  forms  of 
Primitia,  Beyrichia ,  Ulriehicc ,  JEchmina ,  and  Cytherella — several  of 
them  being  closely  allied  as  varieties,  but  all  worthy  of  study  as 
biological  groups,  such  as  have  been  illustrated  from  other  regions 
by  writers  on  the  Ostracoda,  with  a  view  to  the  exact  determina¬ 
tion,  if  possible,  of  species  and  genera,  of  their  local  and  more 
distant  or  regional  distribution,  and  of  their  range  in  time. 
§  2.  References  to  Figures  and  Descriptions  of  Groups  of 
mutually-related  Ostracoda  of  Palaeozoic  Age. 
1.  J.  Barrande.  Syst.  Sil.  Boheme,  vol.  i.  Supplem.  1872. 
Various. 
2.  Fr.  Schmidt.  Mem.  Acad.  Imp.  Sc.  St.-Petersbourg,  ser.  7, 
vol.  xxi.  1873,  Lejyerditioe ;  ibid.  vol.  xxxi.  1883,  Lejper- 
ditice. 
3.  G.  Reuter.  Zeitschr.  Deutsch.  geol.  Gesellsch.  vol.  xxxvii. 
1885,  pp.  621-679,  pis.  xxv.,  xxvi. 
4.  M.  Verworn.  Ibid.  vol.  xxxix.  1887,  pp.  27-31,  pi.  iii. 
5.  J.  Xiesow.  Ibid.  vol.  xl.  1888,  pp.  1-16,  pis.  i.,  ii. ;  Jahrb. 
Geol.  Landesanst.  u.  Bergakad.  Preuss.  1889,  pp.  80-103, 
pis.  xxiii.,  xxiv. 
J  The  drawing  on  stone  for  this  Plate  was  presented  by  Messrs.  Nicholson 
and  Marr. 
