﻿164 
  T. 
  DAVIDSON 
  AND 
  W. 
  KING 
  OUT 
  THE 
  TKIMEKEIAID^. 
  

  

  DlNOBOLTTS 
  MAGNIFICUS, 
  Billings, 
  PL 
  XIX. 
  fig. 
  8. 
  

  

  Obolus 
  canadensis 
  (in 
  part), 
  Billlings, 
  Geol. 
  Survey 
  of 
  Canada 
  for 
  

  

  1857, 
  fig. 
  19 
  (published 
  in 
  1858). 
  

   Obolellina 
  magnrfica, 
  Bill. 
  Can. 
  Nat. 
  for 
  April 
  1872, 
  p. 
  17, 
  fig. 
  7. 
  

   Dinobolus 
  magnificus, 
  Dav. 
  & 
  King, 
  Report 
  of 
  Brighton 
  Meeting 
  

  

  of 
  Brit. 
  Assoc., 
  20th 
  August, 
  1872. 
  

  

  We 
  have 
  not 
  seen 
  specimens 
  of 
  this 
  species. 
  Mr. 
  Billings 
  has 
  

   given 
  the 
  figure 
  of 
  one 
  valve 
  only, 
  showing 
  nothing 
  more 
  than 
  

   its 
  exterior. 
  He 
  states, 
  however, 
  that 
  the 
  " 
  dorsal 
  valve 
  " 
  is 
  " 
  trans- 
  

   versely 
  broad 
  ovate; 
  width 
  about 
  one 
  fourth 
  greater 
  than 
  the 
  

   length, 
  uniformly 
  and 
  moderately 
  convex 
  ; 
  apical 
  angle 
  about 
  130 
  

   degrees 
  ; 
  cardinal 
  edges 
  nearly 
  straight 
  or 
  gently 
  eonvex 
  for 
  about 
  

   one 
  third 
  the 
  length 
  of 
  the 
  shell 
  ; 
  sides 
  and 
  front 
  rounded, 
  the 
  latter 
  

   more 
  broadly 
  than 
  the 
  former. 
  The 
  area 
  seems 
  to 
  be 
  obsolete 
  

   altogether 
  or 
  merely 
  linear 
  ; 
  the 
  ventral 
  valve 
  is 
  depressed 
  eonvex, 
  

   with 
  a 
  large 
  beak 
  slightly 
  incurved 
  ; 
  area 
  with 
  a 
  wide 
  triangular 
  

   peduncular 
  groove, 
  no 
  lateral 
  furrows 
  ; 
  surface 
  of 
  both 
  valves 
  con- 
  

   centrically 
  marked 
  with 
  imbricating 
  lines 
  of 
  growth. 
  In 
  a 
  specimen 
  

   which 
  appears 
  to 
  have 
  been 
  about 
  20 
  lines 
  in 
  length 
  the 
  height 
  of 
  

   the 
  area 
  is 
  nearly 
  3 
  lines." 
  

  

  Dinobolus 
  magnificus, 
  excepting 
  being 
  wider 
  and 
  less 
  long, 
  offers 
  

   a 
  close 
  resemblance 
  to 
  D. 
  transverms. 
  It 
  oecurs 
  in 
  the 
  Black-river 
  

   formation 
  (Lower 
  Silurian) 
  along 
  with 
  J), 
  canadensis. 
  

  

  Dinobolus 
  Schmidti, 
  Dav. 
  & 
  King. 
  PL 
  XIX. 
  figs. 
  5 
  & 
  6. 
  

  

  This 
  species, 
  only 
  known 
  from 
  two 
  specimens, 
  is 
  almost 
  circular 
  ; 
  

   obtusely 
  tapering 
  at 
  the 
  beak 
  : 
  valves 
  moderately 
  convex 
  : 
  surface 
  

   smooth. 
  It 
  closely 
  resembles 
  D. 
  Conradi 
  ; 
  but 
  seemingly 
  differs 
  

   therefrom 
  in 
  being 
  of 
  less 
  width. 
  The 
  pedicle-valve, 
  the 
  only 
  one 
  

   we 
  are 
  acquainted 
  with, 
  possesses 
  impressions 
  characteristic 
  of 
  the 
  

   genus. 
  

  

  Professor 
  P. 
  Schmidt, 
  after 
  whom 
  we 
  have 
  named 
  this 
  species* 
  

   discovered 
  in 
  1873 
  the 
  specimens 
  above 
  noticed 
  at 
  Kirna, 
  Esthonia, 
  

   Russia. 
  They 
  occurred 
  in 
  the 
  Lyckholmer 
  Schicht 
  (2 
  a 
  of 
  Schmidt's 
  

   Classification), 
  which 
  he 
  considers 
  to 
  be 
  nearly 
  equivalent 
  to 
  the 
  

   Caradoc 
  of 
  Great 
  Britain, 
  and 
  the 
  Trenton 
  limestone 
  of 
  North 
  

   America, 
  

  

  Appendix. 
  

  

  a. 
  Lingulops 
  Whiteieldi, 
  Hall. 
  PL 
  XIX. 
  figs. 
  9, 
  9a. 
  

  

  In 
  his 
  recently 
  published 
  " 
  Notes 
  on 
  some 
  new 
  or 
  imperfectly 
  

   known 
  forms 
  among 
  the 
  Brachiopoda," 
  &c, 
  Professor 
  James 
  Hall 
  

   states 
  that 
  " 
  in 
  a 
  late 
  examination 
  of 
  some 
  Lower-Silurian 
  species, 
  

   usually 
  designated 
  as 
  Lingdxa, 
  one 
  of 
  them 
  was 
  found 
  to 
  possess 
  a 
  

   muscular 
  impression 
  differing 
  entirely 
  from 
  any 
  described 
  Linguloid 
  

   species. 
  The 
  ventral 
  (?) 
  valve 
  presents 
  a 
  small 
  area 
  with 
  a 
  narrow 
  

   pedicel-groove 
  ; 
  a 
  large 
  lobed 
  muscular 
  impression, 
  which 
  in 
  the 
  

  

  