﻿140 
  A. 
  E. 
  Verrill 
  — 
  Echinoderms 
  of 
  Northeastern 
  America. 
  

  

  are 
  very 
  numerous 
  and 
  conspicuous 
  over 
  most 
  of 
  the 
  dorsal 
  

   surface, 
  in 
  large 
  clusters. 
  The 
  ventral 
  plates 
  are 
  nearly 
  

   uniformly 
  co 
  vered 
  with 
  slender 
  needle-shaped 
  spinules 
  of 
  

   nearly 
  uniform 
  size, 
  no 
  groups 
  of 
  larger 
  spinules 
  being 
  present 
  

   on 
  them. 
  

  

  The 
  spinules, 
  above 
  and 
  below, 
  as 
  well 
  as 
  the 
  adambulacral 
  

   spines, 
  are 
  decidedly 
  longer 
  and 
  more 
  slender 
  than 
  in 
  P. 
  spinu- 
  

   losa. 
  The 
  upper 
  marginal 
  plates 
  are 
  conspicuous, 
  swollen, 
  

   elongated 
  vertically, 
  but 
  have 
  no 
  special 
  spines. 
  

  

  A 
  row 
  of 
  papulae, 
  between 
  the 
  upper 
  and 
  lower 
  plates. 
  

  

  Rhegaster 
  abtssicola, 
  sp. 
  uov. 
  

  

  B. 
  range, 
  2045 
  fathoms, 
  K 
  lat. 
  37°, 
  W. 
  long. 
  71° 
  54'. 
  

  

  Greater 
  radius, 
  35 
  mm 
  ; 
  lesser 
  14 
  mm 
  ; 
  elevation 
  at 
  center, 
  17 
  mm 
  . 
  

   Form 
  five-rayed, 
  stellate, 
  with 
  the 
  disk 
  flat 
  beneath, 
  tumid 
  

   above, 
  and 
  indented 
  by 
  a 
  distinct 
  groove 
  at 
  the 
  interradial 
  

   angles. 
  Rays 
  tumid 
  at 
  base, 
  with 
  the 
  distal 
  part 
  roundish, 
  

   slender, 
  and 
  uniformly 
  tapered. 
  Abactinal 
  plates 
  rather 
  large, 
  

   concealed 
  by 
  the 
  cuticle, 
  and 
  everywhere 
  bearing 
  small, 
  blunt, 
  

   well-separated, 
  simple 
  spinules, 
  which 
  are 
  more 
  or 
  less 
  covered 
  

   by 
  the 
  integument. 
  Papulae 
  small, 
  scattered 
  singly 
  over 
  most 
  

   of 
  the 
  dorsal 
  surface. 
  The 
  lower 
  marginal 
  plates 
  are 
  small, 
  

   somewhat 
  prominent, 
  and 
  bear 
  an 
  irregular 
  group 
  of 
  six 
  or 
  

   eight 
  small, 
  sharp 
  spinules, 
  which 
  form 
  a 
  distinct 
  border 
  

   along 
  the 
  under 
  edge 
  of 
  the 
  disk 
  and 
  basal 
  half 
  of 
  the 
  rays, 
  but 
  

   disappear 
  gradually 
  before 
  reaching 
  the 
  tips 
  of 
  the 
  rays. 
  

   Actinal 
  plates 
  entirely 
  concealed 
  by 
  the 
  integument 
  ; 
  each 
  one 
  

   bears 
  a 
  divergent 
  group 
  of 
  four 
  to 
  six 
  or 
  more 
  small, 
  sharp, 
  

   rather 
  stout 
  spinules, 
  which 
  are 
  unequal 
  in 
  size. 
  Each 
  adam- 
  

   bulacral 
  plate 
  usually 
  bears 
  an 
  obliquely 
  transverse 
  row 
  of 
  

   about 
  five 
  somewhat 
  long, 
  subacute 
  spinules, 
  of 
  which 
  the 
  

   middle 
  ones 
  are 
  a 
  little 
  longer 
  than 
  the 
  others, 
  and 
  in 
  some 
  

   cases 
  the 
  row 
  is 
  double; 
  the 
  innermost 
  is 
  borne 
  upon 
  the 
  

   inner 
  angle 
  of 
  the 
  plate, 
  which 
  projects 
  somewhat 
  into 
  the 
  

   furrow. 
  The 
  ambulacral 
  feet 
  are 
  large, 
  biserial, 
  and 
  furnished 
  

   with 
  well-developed 
  terminal 
  suckers. 
  The 
  inner 
  end 
  of 
  each 
  

   jaw 
  bears 
  four 
  rather 
  stout, 
  sharp 
  spines, 
  similar 
  to 
  those 
  of 
  the 
  

   adambulacral 
  plates. 
  

  

  A 
  single 
  specimen 
  (No. 
  8140) 
  was 
  taken 
  at 
  station 
  2226, 
  off 
  

   Delaware 
  Bay. 
  

  

  Two 
  allied 
  species 
  (R. 
  Murrayi 
  SI. 
  and 
  B. 
  tumidus 
  

   (Stuxb.) 
  SI. 
  are 
  found 
  at 
  moderate 
  depths 
  on 
  the 
  northern 
  

   European 
  coast 
  ; 
  the 
  last 
  also 
  occurs 
  in 
  the 
  Arctic 
  Ocean. 
  

  

  Family 
  Asterinid^b. 
  

  

  Asterina 
  pygale 
  a 
  Verrill. 
  

  

  This 
  Journal, 
  vol. 
  xvi, 
  p. 
  372, 
  1878. 
  

  

  