﻿SALTER 
  BTTDLEIGH 
  SALTERTON 
  FOSSILS. 
  293 
  

  

  nished, 
  within 
  the 
  beak 
  of 
  one 
  valve 
  at 
  least, 
  with 
  a 
  pair 
  of 
  parallel 
  

   short 
  ridges 
  which 
  border 
  the 
  byssal 
  area. 
  The 
  sides 
  are 
  strictly 
  

   parallel 
  for 
  more 
  than 
  half 
  the 
  length 
  of 
  the 
  shell, 
  and 
  then 
  taper 
  

   gradually 
  and 
  with 
  a 
  very 
  slight 
  curve 
  to 
  the 
  beak, 
  as 
  described 
  by 
  

   Rouault, 
  who 
  however 
  had 
  larger 
  specimens, 
  over 
  2 
  inches 
  long 
  ; 
  ours 
  

   do 
  not 
  reach 
  a 
  length 
  of 
  more 
  than 
  1| 
  inch. 
  

  

  2. 
  Lingula 
  Hawkei, 
  Rouault. 
  PI. 
  XVII. 
  figs. 
  2, 
  3. 
  Marie 
  Rouault, 
  

   loc. 
  cit. 
  p. 
  728. 
  

  

  I 
  think 
  these 
  are 
  small 
  specimens 
  of 
  Rouault's 
  species. 
  Our 
  

   shell 
  is 
  1| 
  inch 
  in 
  length, 
  and 
  barely 
  so 
  wide 
  as 
  long, 
  even 
  in 
  front, 
  

   where 
  it 
  is 
  widest. 
  It 
  is 
  truncate 
  in 
  front 
  and 
  a 
  very 
  little 
  emar- 
  

   ginate 
  ; 
  tapers 
  slowly, 
  with 
  much-curved 
  sides, 
  from 
  the 
  front 
  towards 
  

   the 
  hinge, 
  and 
  is 
  there 
  broadly 
  rounded 
  into 
  the 
  very 
  blunt 
  and 
  in- 
  

   flated 
  beak. 
  Probably 
  older 
  specimens 
  would 
  become 
  still 
  rounder 
  

   in 
  outline. 
  The 
  surface 
  shows 
  at 
  intervals 
  strong 
  ridges 
  of 
  growth, 
  

   most 
  distinct 
  in 
  the 
  outer 
  half 
  and 
  near 
  the 
  margin 
  ; 
  and 
  these 
  are 
  

   crossed 
  by 
  fine 
  radiating 
  lines, 
  with 
  here 
  and 
  there 
  a 
  longitudinal 
  

   ridge 
  among 
  them. 
  Fig. 
  3 
  shows 
  the 
  larger 
  and 
  flatter 
  valve 
  ; 
  it 
  

   has 
  a 
  more 
  produced 
  beak. 
  The 
  other 
  valve 
  is 
  shorter 
  and 
  rounder, 
  

   and 
  has 
  the 
  central 
  area 
  veiy 
  distinct 
  and 
  prominent. 
  

  

  3. 
  Lixgtjla 
  Roitattlti, 
  spec. 
  nov. 
  PI. 
  XVII. 
  figs. 
  4, 
  5. 
  

   [Compare 
  with 
  L. 
  Brimonti, 
  M. 
  Rouault, 
  loc. 
  cit. 
  p. 
  728.] 
  

  

  A 
  most 
  remarkable 
  fossil, 
  and 
  common 
  in 
  the 
  Budleigh 
  Salterton 
  

   pebble 
  -bed. 
  It 
  very 
  much 
  recals 
  the 
  description 
  of 
  L. 
  Brimonti, 
  

   being 
  short, 
  robust, 
  much 
  inflated, 
  wider 
  than 
  long. 
  Rut 
  the 
  

   margin 
  cannot 
  be 
  called 
  circular 
  in 
  any 
  sense 
  ; 
  and, 
  moreover, 
  I 
  

   believe 
  fig. 
  6 
  is 
  the 
  true 
  L. 
  Brimonti, 
  as 
  does 
  also 
  M. 
  de 
  Verneuil. 
  

  

  L. 
  Rouaulti 
  is 
  truly 
  triangular, 
  but 
  with 
  a 
  produced 
  beak, 
  the 
  

   front 
  truncate, 
  the 
  sides 
  very 
  little 
  arched 
  in 
  the 
  smaller, 
  and 
  

   nearly 
  straight 
  in 
  the 
  larger, 
  valve. 
  It 
  is 
  an 
  inch 
  and 
  -^ths 
  long, 
  

   and 
  only 
  -y^-ths 
  broad. 
  Roth 
  valves 
  are 
  highly 
  convex 
  for 
  the 
  genus, 
  

   but 
  the 
  smaller 
  one 
  by 
  far 
  the 
  most 
  so, 
  and 
  regularly 
  inflated 
  from 
  

   the 
  small 
  pointed 
  beak 
  (without 
  ridges 
  to 
  mark 
  out 
  the 
  central 
  area 
  as 
  

   in 
  the 
  next 
  species). 
  A 
  slight 
  depression 
  occurs 
  down 
  the 
  centre. 
  

   In 
  the 
  opposite 
  valve 
  the 
  convexity 
  is 
  less, 
  but 
  the 
  central 
  area 
  is 
  

   still 
  very 
  much 
  raised, 
  and 
  bordered 
  on 
  each 
  side 
  by 
  an 
  angular 
  

   convexity, 
  which 
  is 
  not 
  a 
  ridge, 
  because 
  there 
  is 
  no 
  central 
  depres- 
  

   sion, 
  only 
  a 
  flattening 
  along 
  the 
  middle 
  of 
  the 
  valve. 
  Its 
  sides 
  slope 
  

   steeply 
  to 
  the 
  edge, 
  and 
  form 
  true 
  lateral 
  areas. 
  The 
  edges 
  are 
  very 
  

   sinuous, 
  the 
  side-view 
  showing 
  a 
  strong 
  projection 
  forwards 
  from 
  

   about 
  the 
  middle 
  of 
  the 
  larger 
  or 
  ventral 
  valve. 
  The 
  lines 
  of 
  growth 
  

   are 
  remarkably 
  strong 
  at 
  intervals, 
  and 
  form 
  strong 
  squamous 
  ridges 
  

   on 
  the 
  outer 
  portions 
  of 
  the 
  shell. 
  Between 
  these 
  the 
  surface 
  is 
  rather 
  

   smooth 
  and 
  even, 
  and 
  the 
  numerous 
  and 
  strong 
  radiating 
  striae 
  that 
  

   show 
  themselves 
  on 
  the 
  inner 
  surface 
  of 
  the 
  shell, 
  and 
  permeate 
  its 
  

   substance 
  (see 
  fig. 
  4, 
  4a), 
  are 
  not 
  at 
  all 
  seen 
  on 
  the 
  outer 
  surface. 
  

  

  The 
  muscular 
  scars 
  are 
  strong, 
  and 
  approximate 
  in 
  the 
  dorsal 
  

  

  