﻿380 
  Prof. 
  T. 
  R. 
  Jones 
  on 
  the 
  

  

  varieties 
  clausa 
  &c. 
  (Ann. 
  & 
  Mag. 
  Nat. 
  Hist. 
  April 
  1886, 
  

   pp. 
  354-356, 
  pi. 
  xii. 
  figs. 
  8, 
  9, 
  10), 
  in 
  which 
  the 
  two 
  main 
  

   lobes 
  do 
  not 
  taper 
  off 
  one 
  within 
  the 
  other, 
  but 
  are 
  thick 
  

   below 
  and 
  more 
  or 
  less 
  confluent. 
  The 
  nearest 
  known 
  form, 
  

   however, 
  is 
  Beyrichia 
  gigantea, 
  J., 
  K., 
  & 
  B. 
  (' 
  Monogr. 
  

   Carbonif. 
  Entom.,' 
  Pal. 
  Soc. 
  1874, 
  pi. 
  iv. 
  fig. 
  27, 
  and 
  1884, 
  

   p. 
  88) 
  ; 
  the 
  latter 
  measures 
  A\ 
  millim., 
  the 
  former 
  only 
  lyV 
  

   millim. 
  There 
  is 
  also 
  some 
  resemblance 
  between 
  fig. 
  3 
  and 
  

   Beyrichia 
  Jonesii, 
  Dawson 
  (non 
  Boll), 
  from 
  the 
  Carboniferous 
  

   Limestone 
  of 
  Nova 
  Scotia 
  (' 
  Acadian 
  Geology,' 
  3rd 
  edit. 
  

   1878, 
  p. 
  313, 
  fig. 
  132) 
  ; 
  but 
  in 
  this 
  figure 
  the 
  central 
  lobe 
  is 
  

   much 
  larger, 
  and 
  is 
  surmounted 
  by 
  a 
  small 
  tubercle. 
  

  

  The 
  specimen 
  from 
  Cap 
  Bon-Ami 
  is 
  associated 
  with 
  Mur- 
  

   ch'sonia, 
  a 
  brachiopod, 
  and 
  an 
  obscure 
  fish-bone. 
  

  

  In 
  fig. 
  4 
  (no. 
  26) 
  the 
  confluence 
  of 
  the 
  two 
  great 
  lobes 
  is 
  

   more 
  complete 
  than 
  in 
  any 
  published 
  variety 
  of 
  B. 
  Klwdeni 
  

   except 
  var. 
  scotica 
  (Ann. 
  & 
  Mag. 
  Nat. 
  Hist. 
  1886, 
  pi. 
  xii. 
  

   fig. 
  10). 
  The 
  middle 
  lobe 
  loses 
  to 
  a 
  great 
  degree 
  the 
  isola- 
  

   tion 
  due 
  to 
  the 
  lateral 
  furrows, 
  especially 
  in 
  front 
  and 
  below, 
  

   and 
  becomes 
  rounded. 
  These 
  features 
  are 
  not 
  those 
  of 
  

   Klcedenia 
  Wilckensiana*, 
  to 
  which 
  species 
  this 
  valve 
  has 
  

   at 
  first 
  sight 
  some 
  resemblance. 
  

  

  Fig. 
  5 
  (from 
  specimen 
  no. 
  31) 
  has 
  the 
  middle 
  lobe 
  more 
  

   isolated 
  and 
  longer 
  than 
  it 
  is 
  in 
  fig. 
  4, 
  and 
  the 
  front 
  lobe 
  

   fades 
  away 
  downwards, 
  somewhat 
  like 
  that 
  feature 
  in 
  the 
  

   typical 
  B. 
  Kloedeni, 
  but 
  still 
  more 
  resembling, 
  in 
  this 
  respect, 
  

   B. 
  gigantea 
  above-mentioned. 
  

  

  In 
  fig. 
  6, 
  however, 
  a 
  larger 
  individual 
  (from 
  no. 
  25), 
  the 
  

   ventral 
  coalescence 
  of 
  the 
  lobes 
  is 
  perfect, 
  as 
  in 
  var. 
  tubercu- 
  

   lata 
  (ibid. 
  1886, 
  p. 
  354, 
  pi. 
  xii. 
  fig. 
  8) 
  and 
  in 
  B. 
  gigantea 
  

   (Carbonif. 
  Monogr. 
  1874, 
  pi. 
  iv. 
  fig. 
  28) 
  : 
  but 
  the 
  middle 
  

   lobe 
  is 
  narrower, 
  longer, 
  and 
  more 
  parallel-sided 
  than 
  in 
  those 
  

   and 
  other 
  allied 
  varieties, 
  and 
  much 
  more 
  so 
  than 
  in 
  Kloedenia. 
  

   Figs. 
  3-6 
  moreover 
  show 
  a 
  broad 
  marginal 
  flange, 
  which 
  is 
  

   not 
  seen 
  in 
  the 
  forms 
  just 
  referred 
  to. 
  

  

  I 
  have 
  a 
  fine 
  example 
  like 
  fig. 
  6 
  in 
  a 
  piece 
  of 
  dark 
  grey 
  

   argillaceous 
  limestone, 
  with 
  Cucullrea, 
  from 
  Cap 
  Bon-Ami, 
  

   given 
  to 
  me 
  by 
  Sir 
  J. 
  W. 
  Dawson 
  at 
  Montreal 
  in 
  1884. 
  

  

  In 
  fig. 
  8 
  (from 
  no. 
  28, 
  with 
  Orthonota 
  and 
  Cucullella?), 
  

   excepting 
  the 
  median 
  furrow, 
  which 
  is 
  not 
  very 
  strong, 
  be- 
  

   hind 
  a 
  weak 
  middle 
  lobe, 
  the 
  depressions 
  of 
  the 
  valve 
  merely 
  

   give 
  it 
  an 
  undulating 
  surface, 
  there 
  being 
  one 
  broad 
  curved 
  

   hollow 
  on 
  the 
  hinder 
  moiety 
  separate 
  from 
  the 
  flattish 
  mar- 
  

  

  * 
  See 
  Ann. 
  & 
  Mag. 
  Nat. 
  Hist. 
  ser. 
  6, 
  vol. 
  i. 
  1888, 
  pp. 
  398 
  and 
  £99, 
  

   for 
  remarks 
  on 
  this 
  genus 
  and 
  some 
  of 
  its 
  known 
  species. 
  

  

  