﻿MOLLUSCA. 
  95 
  

  

  sulci 
  cutting 
  across 
  them. 
  The 
  margiu 
  of 
  the 
  valves 
  within 
  is 
  den- 
  

   ticulate 
  everywhere 
  except 
  down 
  the 
  posterior 
  dorsal 
  slope, 
  the 
  

   denticles 
  on 
  the 
  edge 
  of 
  the 
  lunulc 
  heing 
  tiner 
  and 
  closer 
  together 
  

   than 
  elsewhere. 
  The 
  pallial 
  hne 
  is 
  posteriorly 
  nearly 
  straight, 
  or 
  

   even 
  a 
  little 
  inmrved 
  just 
  helbre 
  the 
  commencement 
  of 
  the 
  sinus, 
  

   which 
  is 
  rather 
  deep. 
  The 
  interior 
  is 
  generally 
  somewhat 
  rosy, 
  

   especially 
  towards 
  the 
  heaks. 
  

  

  8. 
  Cytherea 
  (Caryatis) 
  coxeni. 
  (Plate 
  VII. 
  figs. 
  A-A2.) 
  

  

  Shell 
  small, 
  inequilateral, 
  subtrigonally 
  oval, 
  white, 
  variegated 
  

   with 
  pale 
  zigzag 
  brown 
  or 
  reddish 
  lines 
  forming 
  an 
  irregular 
  broken- 
  

   up 
  network. 
  Anterior 
  dorsal 
  margin 
  straightish, 
  much 
  descending, 
  

   sharply 
  curving 
  at 
  the 
  end 
  into 
  the 
  upturned 
  ventral 
  outline. 
  

   Posterior 
  slope 
  much 
  loTiger, 
  somewhat 
  arcuate 
  and 
  less 
  oblique 
  than 
  

   the 
  anterior. 
  Hinder 
  extremity 
  produced, 
  roundly 
  acuminated. 
  

   Lower 
  margin 
  widely 
  curved, 
  about 
  equally 
  ascending 
  at 
  both 
  ends. 
  

   Umbones 
  small, 
  well 
  curved 
  over 
  towards 
  the 
  front. 
  Lunule 
  long- 
  

   ish 
  heart-shaped, 
  a 
  little 
  sunken, 
  slightly 
  elevated 
  along 
  the 
  middle, 
  

   and 
  defined 
  bj- 
  an 
  impressed 
  line. 
  Area 
  indistinct. 
  Surface 
  of 
  the 
  

   valves 
  finely 
  sulcate-striated, 
  the 
  intervening 
  lir<© 
  being 
  somewhat 
  

   rounded, 
  much 
  crowded 
  at 
  the 
  sides, 
  some 
  of 
  them 
  not 
  extending 
  

   quite 
  to 
  the 
  lateral 
  outlines, 
  especially 
  postei'iorly. 
  Central 
  cardinal 
  

   tooth 
  of 
  the 
  left 
  valve 
  thick, 
  triangular, 
  the 
  two 
  others 
  slender 
  and 
  

   lamellar 
  ; 
  posterior 
  in 
  the 
  right 
  valve 
  elongate, 
  the 
  central 
  erect, 
  

   conical, 
  free. 
  Posterior 
  muscular 
  scar 
  nearly 
  circular, 
  the 
  anterior 
  

   narrower, 
  ovate. 
  Pallial 
  sinus 
  moderately 
  deep, 
  rather 
  wide, 
  squarely 
  

   truncated 
  at 
  the 
  end. 
  Length 
  13 
  millim., 
  height 
  10^, 
  diameter 
  7. 
  

  

  Hub. 
  Port 
  Molle, 
  Queensland, 
  14 
  fms. 
  

  

  This 
  species 
  I 
  am 
  unable 
  to 
  identify 
  as 
  the 
  young 
  stage 
  of 
  any 
  

   known 
  larger 
  species. 
  It 
  apparently 
  becomes 
  more 
  pointed 
  behind 
  

   as 
  it 
  increases 
  : 
  so 
  that 
  if 
  it 
  be 
  the 
  early 
  growth 
  of 
  the 
  species, 
  the 
  

   adult 
  form 
  will 
  be 
  much 
  produced 
  at 
  that 
  part. 
  C. 
  minuta, 
  Koch, 
  

   has 
  no 
  coloured 
  pattern 
  and 
  a 
  different 
  pallial 
  sinus. 
  

  

  The 
  form 
  of 
  this 
  species 
  resembles 
  very 
  closely 
  that 
  of 
  C. 
  pura^ 
  

   Dcshayes, 
  a 
  species 
  found 
  at 
  Callao 
  in 
  South 
  America. 
  It 
  is, 
  how- 
  

   ever, 
  more 
  strongly 
  concentricall}^ 
  lirate, 
  is 
  ornamented 
  with 
  pale 
  

   brown 
  zigzag 
  lines 
  and 
  dots, 
  and 
  the 
  form 
  of 
  the 
  pallial 
  sinus 
  is 
  

   (]uite 
  different. 
  

  

  9. 
  Cytherea 
  (Caryatis) 
  albina. 
  

  

  Lamarck 
  ? 
  ; 
  Romei', 
  Monogr. 
  Venus, 
  Novitat. 
  Conch, 
  p. 
  87, 
  pi. 
  23. 
  

   ligs. 
  5-5 
  b. 
  

  

  Bab. 
  Port 
  Molle, 
  Queensland 
  {Coppimjer). 
  

  

  The 
  shell 
  from 
  the 
  above 
  locality 
  agrees 
  with 
  Rcimcr's 
  detcrmi- 
  

   ruition 
  of 
  this 
  species 
  ; 
  and 
  two 
  specimens 
  from 
  Cape 
  York 
  in 
  the 
  

   ^Museum, 
  named 
  Z>. 
  buUata 
  of 
  Sowerby 
  by 
  Deshayes 
  (Cat. 
  Conch. 
  

   Biv. 
  p. 
  70), 
  are 
  also 
  referable 
  to 
  it, 
  for 
  they 
  have 
  not 
  the 
  straightish 
  

   ventral 
  margin 
  of 
  that 
  species. 
  

  

  