﻿Polyzoa 
  of 
  the 
  St. 
  Lawrence. 
  431 
  

  

  lated 
  ; 
  orifice 
  (primary) 
  semicircular, 
  lower 
  margin 
  straight 
  ; 
  

   (secondary) 
  orbicular, 
  with 
  a 
  deep 
  sinus, 
  tapering 
  off 
  gradu- 
  

   ally 
  to 
  a 
  point 
  below 
  ; 
  peristome 
  thickened, 
  slightly 
  raised, 
  

   on 
  each 
  side 
  of 
  the 
  sinus 
  a 
  nodulous 
  collar-like 
  rising. 
  

   cerium 
  subglobose, 
  prominent 
  (when 
  not 
  concealed 
  by 
  the 
  

   progress 
  of 
  calcification), 
  a 
  projecting 
  rim 
  round 
  the 
  oral 
  

   arch 
  ; 
  surface 
  smooth 
  or 
  minutely 
  granulated. 
  

  

  Avicularia 
  none. 
  

  

  There 
  is 
  considerable 
  variation 
  in 
  the 
  form 
  of 
  the 
  secondary 
  

   orifice, 
  dependent 
  upon 
  age 
  ; 
  in 
  the 
  adult 
  state 
  it 
  is 
  as 
  

   described 
  above. 
  Yo 
  11112; 
  fresh 
  colonies 
  are 
  reddish 
  brown, 
  

   but 
  in 
  older 
  specimens 
  the 
  surface 
  is 
  of 
  a 
  dull 
  white 
  colour. 
  

  

  Verrill 
  has 
  referred 
  Packard's 
  species 
  to 
  Escharoidea 
  Sarsii, 
  

   but 
  the 
  history 
  of 
  the 
  development 
  of 
  the 
  cell 
  is 
  quite 
  differ- 
  

   ent 
  in 
  the 
  two 
  forms, 
  and 
  in 
  no 
  stage 
  of 
  growth 
  is 
  there 
  any 
  

   trace 
  of 
  the 
  oral 
  avicularium 
  which 
  is 
  so 
  essential 
  a 
  character 
  

   of 
  the 
  latter. 
  

  

  MUCKONELLA, 
  Hilicks. 
  

   Mucronella 
  spinidifera, 
  n. 
  sp. 
  (PI. 
  XXI. 
  fig. 
  3.) 
  

  

  Zooeria 
  rudely 
  ovate, 
  often 
  much 
  elongated 
  and 
  truncate 
  

   below, 
  sometimes 
  pyriform, 
  variable 
  in 
  shape 
  and 
  size, 
  quin- 
  

   cuncial, 
  but 
  not 
  regularly 
  so, 
  very 
  convex 
  and 
  divided 
  by 
  

   deep 
  sutures, 
  strongly 
  calcified 
  ; 
  surface 
  thickly 
  covered 
  with 
  

   small 
  granules, 
  shining 
  ; 
  orifice 
  well 
  arched 
  above, 
  the 
  sides 
  

   curved 
  outwards, 
  lower 
  margin 
  straightish, 
  with 
  a 
  slight 
  

   elevation 
  in 
  the 
  centre 
  which 
  is 
  carried 
  up 
  into 
  a 
  very 
  small 
  

   spinule 
  ; 
  peristome 
  unarmed 
  and 
  not 
  elevated. 
  cerium 
  in- 
  

   conspicuous, 
  subimmersed, 
  rounded, 
  broad 
  in 
  proportion 
  to 
  its 
  

   height 
  ; 
  surface 
  granular. 
  Avicularia 
  none. 
  

  

  Colony 
  of 
  a 
  reddish 
  colour. 
  

  

  This 
  is 
  a 
  somewhat 
  striking 
  form. 
  The 
  colour, 
  the 
  glisten- 
  

   ing 
  granular 
  surface, 
  the 
  prominent 
  deeply-divided 
  cells, 
  and 
  

   the 
  peculiar 
  character 
  of 
  the 
  orifice, 
  with 
  its 
  single 
  spinule 
  on 
  

   the 
  lower 
  margin, 
  combine 
  to 
  give 
  it 
  a 
  very 
  distinctive 
  aspect. 
  

   So 
  far 
  as 
  I 
  know 
  it 
  is 
  undescribed. 
  

  

  Hub. 
  On 
  shells, 
  stones, 
  &c. 
  

  

  Family 
  Eucratiidae. 
  

   . 
  Sckupakia, 
  Hiiicks. 
  

   Scruparia 
  clavata, 
  Hi 
  neks. 
  

  

  This 
  is 
  an 
  interesting 
  addition 
  to 
  the 
  fauna 
  of 
  the 
  St. 
  

   Lawrence. 
  S. 
  clavata 
  was 
  first 
  discovered 
  in 
  Filey 
  Bay, 
  on 
  

  

  