﻿WEIGHT 
  AND 
  ADAMS 
  MALTESE 
  ECBTSrODERMS. 
  471 
  

  

  The 
  Upper 
  Limestone 
  is 
  divisible 
  into 
  three 
  well-marked 
  strata 
  

   or 
  varieties. 
  1st. 
  a. 
  The 
  upper 
  stratum 
  presents 
  a 
  rubbly 
  broken- 
  

   up 
  appearance 
  of 
  diverse 
  density, 
  open 
  more 
  or 
  less 
  with 
  fissures 
  arid 
  

   cavities 
  lined 
  with 
  calcareous 
  incrustations. 
  Fossils 
  are 
  abundant 
  in 
  

   this 
  stratum, 
  consisting 
  chiefly 
  of 
  Lithodomi, 
  casts 
  of 
  Voluta, 
  Trochus, 
  

   Haliotis, 
  Cidaris 
  Melitensis, 
  Forbes, 
  Psammechinus 
  Duciei, 
  Wr., 
  and 
  

   other 
  Echinidm, 
  which 
  will 
  be 
  described 
  in 
  the 
  sequel. 
  In 
  the 
  faults 
  

   and 
  dislocations, 
  as 
  well 
  as 
  in 
  the 
  highest 
  parts 
  of 
  the 
  Island, 
  this 
  

   stratum 
  bears 
  all 
  the 
  marks 
  of 
  having 
  been 
  much 
  disturbed 
  during 
  

   the 
  upheavals 
  and 
  depressions 
  to 
  which 
  the 
  Island 
  was 
  subject 
  ; 
  in 
  

   fact, 
  its 
  mashed 
  and 
  fractured 
  appearance 
  may 
  be 
  said 
  to 
  be 
  owing 
  

   entirely 
  to 
  these 
  causes, 
  inasmuch 
  as 
  in 
  the 
  downcast 
  portions 
  of 
  

   the 
  Island 
  it 
  is 
  so 
  broken 
  up 
  as 
  to 
  have 
  lost 
  all 
  appearance 
  of 
  com- 
  

   pactness, 
  presenting 
  a 
  crumbling 
  and 
  disordered 
  mass, 
  which 
  the 
  

   earlier 
  writers 
  described 
  as 
  shale. 
  The 
  more 
  durable 
  and 
  varie- 
  

   gated 
  portions 
  of 
  this 
  bed 
  and 
  No. 
  5, 
  such 
  as 
  are 
  met 
  with 
  in 
  the 
  

   quarries 
  of 
  Ras 
  il 
  Kala, 
  Gozo, 
  pass 
  under 
  the 
  name 
  of 
  Gozo 
  marble, 
  

   and 
  continue 
  to 
  be 
  in 
  repute 
  for 
  monuments 
  and 
  architectural 
  

   purposes. 
  

  

  2nd. 
  b. 
  This 
  variety 
  is 
  a 
  yellowish-white 
  calcareous 
  sandstone, 
  

   more 
  or 
  less 
  indurated 
  ; 
  it 
  is 
  seen 
  to 
  perfection 
  in 
  the 
  cliffs 
  N.W. 
  of 
  

   Citta 
  Yecchia, 
  where 
  it 
  abounds 
  with 
  casts 
  of 
  Shells 
  and 
  is 
  burnt 
  

   for 
  lime. 
  Its 
  characteristic 
  fossils 
  are 
  ScMzaster 
  eurynotus 
  and 
  S. 
  

   Parlcinsoni 
  ; 
  these 
  are 
  often 
  met 
  with 
  in 
  fragments 
  strewn 
  in 
  long 
  

   lines 
  across 
  the 
  faces 
  of 
  cliff- 
  sections, 
  resembling 
  the 
  washings 
  of 
  a 
  

   sea-coast. 
  The 
  softer 
  parts 
  of 
  this 
  variety 
  give 
  off 
  carbonic 
  acid 
  

   when 
  immersed 
  in 
  water. 
  Although 
  most 
  commonly 
  occupying 
  an 
  

   intermediate 
  position 
  between 
  the 
  last 
  and 
  next 
  stratum, 
  this 
  variety 
  

   may 
  be 
  wanting. 
  

  

  3rd. 
  c, 
  or 
  Coralline 
  stratum, 
  is 
  usually 
  a 
  reddish-white 
  rock, 
  

   which 
  becomes 
  soft 
  and 
  dark-coloured 
  in 
  its 
  lower 
  portion 
  ; 
  it 
  abounds 
  

   with 
  organic 
  remains, 
  chiefly 
  fragments 
  of 
  Crustacea 
  and 
  various 
  

   species 
  of 
  Mollusca 
  and 
  Echinodermata, 
  with 
  button-shaped 
  teeth 
  

   of 
  Pycnodont 
  fishes. 
  The 
  Coralline 
  stratum 
  is 
  a 
  durable 
  rock, 
  

   except 
  towards 
  its 
  transition 
  into 
  the 
  Sand-bed. 
  In 
  that 
  situation 
  

   it 
  is 
  very 
  fossiliferous, 
  containing 
  abundance 
  of 
  teeth 
  of 
  Squalidce, 
  

   fragments 
  of 
  Cetacean 
  bones, 
  beds 
  of 
  Astrcece, 
  and 
  several 
  species 
  of 
  

   Terebratulce. 
  From 
  the 
  abundance 
  of 
  Sharks' 
  teeth, 
  especially 
  those 
  

   of 
  the 
  gigantic 
  Carcharodon 
  megcdodon, 
  it 
  would 
  appear 
  that 
  these 
  

   monsters 
  began 
  to 
  die 
  out 
  then, 
  as 
  none 
  of 
  their 
  teeth, 
  to 
  the 
  best 
  

   of 
  my 
  knowledge, 
  have 
  been 
  found 
  in 
  the 
  strata 
  1 
  and 
  2 
  of 
  the 
  Upper 
  

   Limestone. 
  

  

  The 
  above 
  strata 
  are 
  not 
  invariably 
  met 
  with 
  in 
  every 
  section 
  ; 
  

   sometimes 
  one 
  or 
  both 
  of 
  the 
  upper 
  strata 
  may 
  be 
  wanting 
  and 
  are 
  

   often 
  denuded. 
  The 
  measurements 
  of 
  the 
  various 
  beds 
  differ 
  indi- 
  

   vidually 
  to 
  such 
  an 
  extent 
  as 
  to 
  lead 
  me 
  to 
  consider 
  that 
  any 
  

   statement 
  as 
  to 
  the 
  average 
  thickness 
  of 
  a 
  bed 
  must 
  be 
  received 
  as 
  

   being 
  only 
  a 
  faint 
  approximation 
  to 
  the 
  truth. 
  This 
  assertion 
  was 
  

   fully 
  borne 
  out 
  by 
  a 
  late 
  expedition, 
  made 
  on 
  purpose 
  to 
  test 
  the 
  

   correctness 
  of 
  Capt. 
  Spratt's 
  observations 
  on 
  that 
  head. 
  

  

  