﻿138 
  A. 
  E. 
  Verrill 
  — 
  Echinoderms 
  of 
  Northeastern 
  America. 
  

  

  species, 
  which 
  is 
  similar 
  in 
  size 
  and 
  general 
  appearance. 
  The 
  

   present 
  form 
  has 
  a 
  thinner 
  margin 
  with 
  the 
  plates 
  poorly 
  

   developed. 
  The 
  marginal 
  spines 
  are 
  more 
  or 
  less 
  abortive. 
  

   The 
  long, 
  slender 
  dorsal 
  papulse 
  are 
  confined 
  to 
  two 
  petaloid 
  

   bands 
  on 
  each 
  raj, 
  leaving 
  the 
  median 
  area 
  bare. 
  There 
  are 
  

   two 
  adambulacral 
  spines 
  on 
  the 
  inner 
  edge 
  of 
  each 
  plate, 
  side 
  

   by 
  side, 
  and 
  an 
  outer 
  transverse 
  series 
  of 
  two 
  or 
  three. 
  The 
  

   integument 
  is 
  firm, 
  thick, 
  and 
  glabrous, 
  and 
  when 
  dried 
  it 
  

   shows 
  numerous 
  microscopic 
  spicules 
  on 
  the 
  surface. 
  The 
  

   radial 
  grooves 
  are 
  conspicuous 
  and 
  numerous 
  ; 
  one 
  runs 
  from 
  

   between 
  all 
  the 
  adambulacral 
  plates 
  and 
  marginal 
  plates. 
  The 
  

   rudimentary 
  abactinal 
  and 
  actinal 
  plates 
  are 
  much 
  less 
  devel- 
  

   oped 
  than 
  in 
  the 
  next 
  species. 
  

  

  The 
  above 
  characters 
  warrant 
  the 
  establishment 
  of 
  a 
  new 
  

   subgenus, 
  or 
  perhaps 
  a 
  genus, 
  for 
  this 
  species. 
  I 
  propose 
  to 
  

   name 
  it 
  Chondraster. 
  

  

  PORANIA 
  INSIGNIS, 
  Sp. 
  IIOV. 
  

  

  Porania 
  grandis 
  (pars) 
  Verrill 
  Explorations 
  made 
  by 
  the 
  Albatross 
  in 
  1883, 
  

   p. 
  542, 
  pi. 
  15, 
  figs. 
  45, 
  45 
  a 
  , 
  1885. 
  

  

  B. 
  range, 
  65 
  to 
  373 
  fath. 
  Most 
  common 
  in 
  100 
  to 
  250 
  fath. 
  

   Chiefly 
  in 
  the 
  warm 
  area. 
  Taken 
  at 
  numerous 
  stations, 
  from 
  

   K 
  lat 
  41° 
  28' 
  30" 
  to 
  36° 
  38' 
  30". 
  It 
  has, 
  also, 
  been 
  taken 
  

   several 
  times 
  by 
  the 
  Gloucester 
  fishermen, 
  on 
  the 
  Banks. 
  

  

  A 
  large 
  pentagonal 
  species 
  with 
  convex 
  disk 
  and 
  short 
  rays. 
  

   Radii 
  of 
  an 
  average 
  specimen 
  70 
  mm 
  and 
  34r 
  mm 
  . 
  Dorsal 
  surface 
  

   smooth, 
  with 
  a 
  tough, 
  leathery 
  integument, 
  without 
  visible 
  

   plates 
  or 
  spines, 
  except 
  a 
  cluster 
  of 
  small 
  spinules 
  around 
  the 
  

   "anal" 
  pore. 
  Papulae 
  conspicuous, 
  elongated 
  ; 
  they 
  are 
  most 
  

   abundant 
  along 
  the 
  sides 
  of 
  the 
  rays, 
  but 
  do 
  not 
  form 
  very 
  

   definite 
  bands, 
  though 
  the 
  median 
  line 
  of 
  the 
  rays 
  is 
  mostly 
  

   bare 
  ; 
  a 
  single 
  or 
  double 
  row 
  of 
  papulse 
  extends 
  along 
  the 
  mar- 
  

   gins, 
  between 
  the 
  upper 
  and 
  lower 
  marginal 
  plates, 
  which 
  are 
  

   somewhat 
  prominent, 
  but 
  covered 
  by 
  thick 
  cuticle. 
  The 
  lower 
  

   plates 
  carry 
  a 
  row 
  of 
  three 
  or 
  four 
  sharp, 
  conical, 
  skin-covered 
  

   spinules, 
  which 
  form 
  the 
  sharp 
  edge 
  of 
  the 
  disk 
  ; 
  distally 
  the 
  

   number 
  decreases 
  to 
  two, 
  and 
  finally 
  to 
  one. 
  Each 
  adambula- 
  

   cral 
  plate 
  bears 
  a 
  transverse 
  row 
  of 
  three 
  or 
  two 
  stout, 
  short, 
  

   divergent 
  spines, 
  in 
  irregular 
  alternation 
  ; 
  they 
  are 
  somewhat 
  

   webbed 
  at 
  base 
  ; 
  the 
  outer 
  one 
  is 
  stoutest 
  and 
  often 
  gouge- 
  

   shaped 
  or 
  even 
  double 
  at 
  the 
  blunt 
  tip. 
  Each 
  jaw 
  bears 
  two 
  

   oral, 
  partly 
  webbed, 
  skin-covered, 
  short 
  spines, 
  and 
  two 
  or 
  three 
  

   on 
  each 
  side. 
  The 
  actinal 
  radial 
  furrows 
  are 
  strongly 
  marked 
  ; 
  

   they 
  run 
  from 
  between 
  all 
  the 
  marginal 
  plates, 
  but 
  only 
  

   between 
  alternate 
  adambulacral 
  plates. 
  

  

  Young 
  specimens 
  of 
  this 
  species, 
  when 
  15 
  to 
  20 
  mm 
  in 
  diam- 
  

   eter, 
  have 
  more 
  or 
  less 
  numerous, 
  small, 
  scattered, 
  simple 
  spines, 
  

   both 
  on 
  the 
  dorsal 
  and 
  ventral 
  plates 
  ; 
  these 
  plates 
  are 
  dis- 
  

  

  

  