294 
PROP.  T.  R.  JONES  ON  SOME  PALEOZOIC  [Aug.  1 893, 
1.  Ulrichia  Nicholsoni,  sp.  nov.  (PI.  XII.  fig.  15.) 
Size. — Length  *68  millim.,  height  *56  millim. 
The  two  knobs  on  this  subquadrate  valve  seem  to  be  an  almost 
extravagant  outcome  of  the  Ulrichian  form,  the  pair  of  monticules 
occup}ing  all  the  dorsal  region  with  their  broad,  short  elevations, 
divided  by  a  wide  triangular  opening. 
This  species  is  named  after  Prof.  H.  A.  Nicholson,  D.Sc.,  E.G.S., 
who  has  long  been  one  of  the  most  enthusiastic  workers  in  the 
Lake  District. 
Locality. — “  Pusgill.” 
2.  Ulrichia  Marrii,  sp.  nov.  (PI.  XII.  fig.  16.) 
Size. — Length  '56  millim.,  height  ’44  millim. 
The  outgrowths  on  this  valve  form  two  oblique,  subeylindrical, 
horn-like  processes,  rising  from  the  anterior  (?)  moiety,  and,  if  this 
be  the  antero-dorsal  region,  they  point  backwards,  with  a  narrow 
space  between  them. 
Named  after  Mr.  J.  E.  Marr,  F.E.S.,  Sec.G.S.,  who  has  greatly 
aided  in  the  elucidation  of  the  geology  and  palaeontology  of  the 
Lake  District. 
Locality. — u  Dufton.” 
V.  Genus  aEchmina,  Jones  &  Holl,  1869. 
1.  2Echhina  obtusa,  sp.  nov.  (PI.  XII.  figs.  17  «,  c,  &  18.) 
Size. — Eig.  17 :  Length  '44  millim.,  height  *36  millim. 
Eig.  18 :  Length  *76  millim.,  height  *6  millim.,  thickness 
•4  millim. 
Nearly  semicircular  on  its  ventral  border  ;  the  valves  protrude 
dorsally  in  a  thick,  blunt  process,  which  probably  bears  a  close 
relationship  to  the  neat,  short,  triangular,  horn-like  process  in 
PEchmina  brevicornis ,l  Jones,  but  the  dorsal  projection  differs  from 
the  former  in  its  lumpy,  almost  inelegant  shape,  in  involving  so 
much  more  of  the  hinge-line,  and  in  giving  a  subtriangular  outline 
to  the  valve. 
In  the  habit  and  make  of  the  valves  there  is  some  likeness  in 
figs.  15-18  ;  but  how  far  they  indicate  an  alliance  between  Ulrichia 
and  JEclimina  is  not  at  all  clear. 
That  Ulrichia- like  forms  may  vary  in  the  number  of  their 
tubercles  is  possible.  Primitia  timicla ,2  Barrande,  looks  like  a  one- 
tubercled  Ulrichia  (if  such  might  be),  and  is  associated  with  Ulrichia 
perforata  (Barrande),  mentioned  above,  in  the  black  shales  of  the 
Band  d  3,  near  Trubin. 
Locality. — “  Pusgill.” 
1  Ann.  Mag.  Nat.  Hist.  ser.  5,  vol.  xix.  1887,  p.  413,  pi.  xiii.  fig.  8. 
2  ‘Syst.  Sil.  Boheme,’  vol.  i.  Suppl.  1872,  p.  553,  pi.  xxvii.  fig.  11. 
