﻿1864.] 
  SALTER 
  — 
  LINGULA-FLAG 
  FOSSILS. 
  241 
  

  

  ferous 
  beds, 
  taken 
  carefully 
  by 
  my 
  friend 
  Mr. 
  Hicks, 
  who 
  has 
  noted 
  

   the 
  exact 
  distribution 
  of 
  the 
  fossils 
  in 
  the 
  several 
  beds, 
  and 
  quite 
  

   lately 
  discovered 
  new 
  forms, 
  which 
  I 
  hope 
  to 
  examine 
  in 
  situ 
  and 
  

   describe 
  for 
  the 
  next 
  volume 
  of 
  the 
  Journal. 
  

  

  In 
  a 
  short 
  paper, 
  read 
  last 
  winter 
  by 
  Mr. 
  Henry 
  Hicks 
  to 
  the 
  Geo- 
  

   logical 
  Society 
  of 
  Liverpool, 
  it 
  was 
  remarked 
  that 
  the 
  fossils 
  occurred 
  

   in 
  distinct 
  beds. 
  The 
  fry 
  ? 
  of 
  the 
  Trilobites 
  and 
  the 
  Lingulella 
  

   Davisii, 
  both 
  of 
  very 
  small 
  size, 
  occur 
  lower 
  down 
  than 
  the 
  great 
  

   Trilobites, 
  and 
  the 
  Theca 
  lowest 
  of 
  all, 
  to 
  within 
  100 
  feet 
  of 
  the 
  grey 
  

   Cambrian 
  rock 
  on 
  the 
  west 
  side 
  of 
  the 
  harbour, 
  and 
  fully 
  200 
  feet 
  

   lower 
  than 
  the 
  bands 
  of 
  the 
  Paradoxides. 
  The 
  beds 
  which 
  contain 
  

   the 
  Lingulella, 
  moreover, 
  contain 
  carbonate 
  of 
  lime 
  in 
  abundance, 
  so 
  

   much 
  so 
  as 
  to 
  produce 
  strong 
  effervescence 
  with 
  acids. 
  This 
  is 
  not 
  

   the 
  case 
  in 
  the 
  other 
  beds, 
  but 
  is 
  worthy 
  of 
  notice, 
  as 
  calcareous 
  

   matter 
  is 
  very 
  scarce 
  in 
  the 
  Primordial 
  zone 
  in 
  Britain, 
  though 
  abun- 
  

   dant 
  in 
  Sweden 
  in 
  rocks 
  of 
  like 
  age. 
  There 
  are 
  also 
  beds 
  of 
  con- 
  

   temporaneous 
  trap, 
  as 
  shown 
  in 
  Mr. 
  Hicks's 
  measured 
  section 
  of 
  

   Porth-y-Bhaw, 
  given 
  above 
  (p. 
  240). 
  Interbedded 
  trap 
  has 
  not 
  

   previously 
  been 
  described 
  from 
  the 
  Lingula-flags, 
  though 
  I 
  have 
  seen 
  

   it 
  occurring 
  rarely 
  near 
  Criccieth 
  in 
  North 
  Wales. 
  

  

  EXPLANATION 
  OF 
  PLATE 
  XIII. 
  

  

  Illustrative 
  of 
  Lower 
  Lingula-flag 
  Fossils. 
  

  

  Fig. 
  1. 
  Paradoxides 
  Davidis, 
  Salter. 
  Half-grown 
  specimen 
  of 
  the 
  natural 
  size 
  

   (left 
  side 
  restored 
  from 
  specimens 
  showing 
  the 
  whole 
  of 
  the 
  right 
  

   side) 
  : 
  a, 
  the 
  labrum, 
  attached 
  by 
  a 
  soldered 
  suture 
  to 
  the 
  hypostome, 
  

   and 
  bent 
  back 
  forcibly 
  from 
  the 
  under 
  side 
  (cabinet 
  of 
  Mr. 
  J. 
  E. 
  Lee). 
  

   Tail 
  of 
  ordinary 
  variety, 
  showing 
  the 
  great 
  sabre-shaped 
  pro- 
  

  

  cesses, 
  b, 
  b, 
  with 
  the 
  body-rings 
  in 
  outline 
  (British 
  Museum). 
  

  

  Variety 
  with 
  an 
  abbreviated 
  hinder 
  pair 
  of 
  pleurae 
  to 
  the 
  body 
  

  

  (this 
  specimen 
  has 
  unfortunately 
  been 
  lost) 
  

  

  4. 
  Anopolenus 
  Henrici, 
  gen. 
  et 
  spec. 
  nov. 
  : 
  a, 
  largest 
  head 
  known 
  (Brit. 
  

  

  Mus.) 
  ; 
  b, 
  tail 
  (Mr. 
  H. 
  W. 
  EdgelFs 
  collection) 
  ; 
  c, 
  body-ring. 
  

  

  5. 
  . 
  Body, 
  rings, 
  and 
  part 
  of 
  head 
  (Brit. 
  Mus.). 
  

  

  6. 
  Conocoryphe 
  ? 
  variolaris, 
  spec. 
  nov. 
  : 
  a, 
  natural 
  size 
  (Brit. 
  Mus.) 
  ; 
  b, 
  

  

  outline 
  restored 
  from 
  a 
  less 
  perfect 
  specimen, 
  but 
  snowing 
  fourteen 
  

  

  body-rings 
  and 
  a 
  portion 
  of 
  the 
  tail 
  

  

  la. 
  . 
  Head 
  (Brit. 
  Mus.). 
  

  

  lb. 
  . 
  Young 
  specimen 
  (Brit. 
  Mus.). 
  

  

  8. 
  Agnostus 
  princess 
  : 
  a, 
  natural 
  size 
  (Mr. 
  Salter's 
  cabinet) 
  ; 
  b, 
  outline 
  

  

  restored 
  from 
  good 
  specimens 
  in 
  Mus. 
  Pract. 
  Geology. 
  

  

  9. 
  Holocephalina 
  Primordialis, 
  gen. 
  et 
  spec. 
  nov. 
  (Brit. 
  Mus.) 
  : 
  a, 
  natural 
  

  

  size 
  ; 
  b, 
  enlarged 
  to 
  show 
  the 
  full 
  form. 
  

  

  10. 
  Theca 
  corrugata, 
  spec. 
  nov. 
  (Brit. 
  Mus.), 
  natural 
  size. 
  

  

  11. 
  Fry 
  of 
  some 
  larger 
  Trilobite, 
  ? 
  Microdiscus 
  punctatus, 
  spec, 
  nov 
  : 
  a, 
  head 
  

  

  and 
  tail- 
  pieces, 
  abundant 
  in 
  the 
  Slates 
  of 
  Porth-y-Ehaw 
  (Brit. 
  Mus.) 
  ; 
  

   b, 
  head 
  magnified 
  ; 
  c, 
  perfect 
  form 
  (Mr. 
  Hicks's 
  cabinet). 
  

  

  12. 
  Protospongia 
  fenestrata, 
  gen. 
  et 
  spec. 
  nov. 
  (Brit. 
  Mus.) 
  : 
  a, 
  natural 
  

  

  size 
  ; 
  b, 
  spiculge 
  magnified 
  four 
  diameters. 
  The 
  branches 
  cross 
  at 
  

   rather 
  too 
  obtuse 
  an 
  angle 
  ; 
  they 
  should 
  not 
  be 
  more, 
  on 
  an 
  average, 
  

   than 
  80°. 
  

  

  