﻿386 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEU2L 
  tol. 
  44. 
  

  

  by 
  Th6el, 
  1905). 
  It 
  is 
  remarkable 
  that 
  this 
  characteristically 
  Arctic 
  

   form 
  extends 
  southward 
  along 
  the 
  American 
  coast 
  in 
  shallow 
  water 
  

   as 
  far 
  as 
  IMassachusetts 
  Bay, 
  and 
  in 
  deeper 
  waters 
  as 
  far 
  south 
  as 
  

   about 
  40° 
  north 
  latitude. 
  

  

  Specimens 
  that 
  I 
  have 
  examined 
  from 
  the 
  extreme 
  north 
  (South 
  

   Gatt, 
  northwestern 
  Spitzbergen, 
  latitude 
  79° 
  40' 
  N., 
  7 
  fathoms, 
  and 
  

   others 
  from 
  Spitzbergen 
  Sea 
  dredged 
  by 
  the 
  U. 
  S. 
  S. 
  Alliance 
  in 
  1881) 
  

   do 
  not 
  differ 
  materially 
  from 
  those 
  found 
  in 
  JMassachusetts 
  Bay. 
  

  

  It 
  occurs 
  usually 
  at 
  depths 
  of 
  less 
  than 
  100 
  fathoms, 
  though 
  Theel 
  

   records 
  a 
  specimen 
  from 
  Umanak, 
  Greenland, 
  from 
  200 
  fathoms, 
  and 
  

   it 
  has 
  been 
  found 
  south 
  of 
  Cape 
  Cod 
  in 
  480 
  and 
  1,098 
  fathoms. 
  

  

  The 
  specimens 
  in 
  the 
  United 
  States 
  National 
  Museum 
  differ 
  only 
  

   in 
  minor 
  details 
  (size, 
  color) 
  from 
  Keferstein's 
  (1865) 
  description 
  of 
  

   Ph. 
  horeale, 
  which 
  has 
  been 
  identified 
  by 
  Danielssen 
  and 
  Koren 
  as 
  

   Ph. 
  eremita 
  (Sars). 
  These 
  differences 
  are 
  (1) 
  the 
  slightly 
  smaller 
  size 
  

   of 
  the 
  specimens 
  in 
  the 
  National 
  Museum, 
  none 
  of 
  which 
  is 
  more 
  

   than 
  25 
  or 
  30 
  mm. 
  in 
  total 
  length, 
  including 
  a 
  slight 
  allowance 
  for 
  

   contraction, 
  although 
  it 
  is 
  quite 
  possible 
  that 
  the 
  living 
  animal 
  may 
  

   measure 
  20 
  to 
  50 
  mm., 
  which 
  Selenka 
  (1883) 
  gives 
  as 
  the 
  length 
  of 
  

   Ph. 
  eremita. 
  (2) 
  The 
  introvert 
  in 
  the 
  specimens 
  from 
  off 
  the 
  New 
  

   England 
  coast 
  is 
  shorter 
  than 
  the 
  trunk 
  (pi. 
  58, 
  fig. 
  4), 
  whereas 
  in 
  

   Ph. 
  eremita 
  ( 
  = 
  horeale) 
  it 
  is 
  said 
  to 
  be 
  as 
  long 
  as 
  or 
  longer 
  than 
  the 
  

   trunk. 
  The 
  dimensions 
  given 
  by 
  Keferstein, 
  however 
  (trunk 
  18 
  mm., 
  

   introvert 
  15 
  mm.), 
  agree 
  as 
  to 
  proportions 
  with 
  the 
  specimens 
  which 
  

   I 
  have 
  examined. 
  (3) 
  I 
  find 
  no 
  gray, 
  yellow, 
  or 
  yellowish-brown 
  

   pigment 
  spots 
  on 
  the 
  specimens 
  (preserved 
  in 
  alcohol) 
  that 
  I 
  have 
  

   examined, 
  such 
  as 
  have 
  been 
  found 
  in 
  this 
  species. 
  

  

  The 
  skin 
  is 
  usually 
  dark 
  grayish- 
  or 
  yellowish-brown 
  and, 
  in 
  

   some 
  specimens, 
  has 
  a 
  slight 
  iridescence. 
  The 
  most 
  constant 
  and 
  

   striking 
  characteristic 
  of 
  the 
  skin 
  is 
  the 
  occurrence 
  of 
  parallel 
  trans- 
  

   verse 
  ridges 
  and 
  furrows 
  (pi. 
  58, 
  fig. 
  4) 
  which 
  everywhere 
  encircle 
  the 
  

   body, 
  but 
  are 
  especially 
  constant 
  at 
  the 
  posterior 
  extremity, 
  which 
  

   in 
  some 
  cases 
  is 
  raised 
  into 
  a 
  knob-shaped 
  elevation 
  surrounded 
  by 
  

   concentric 
  ridges. 
  In 
  many 
  individuals 
  the 
  transverse 
  ridges 
  are 
  

   broken, 
  particularly 
  at 
  the 
  posterior 
  extremity 
  of 
  the 
  body 
  and 
  at 
  the 
  

   base 
  of 
  the 
  introvert, 
  by 
  less 
  prominent 
  longitudinal 
  ridges. 
  

  

  Very 
  minute, 
  finger-shaped 
  papillae 
  (in 
  many 
  specimens 
  darker 
  

   than 
  the 
  rest 
  of 
  the 
  skin, 
  and 
  hence 
  easily 
  visible 
  with 
  a 
  lens) 
  are 
  

   scattered 
  somewhat 
  sparsely, 
  but 
  rather 
  evenly, 
  over 
  the 
  surface. 
  

   The 
  papillae 
  are 
  somewhat 
  more 
  abundant, 
  however, 
  at 
  the 
  base 
  of 
  

   the 
  mtrovert 
  and 
  near 
  the 
  posterior 
  extremity 
  of 
  the 
  trunk 
  than 
  

   elsewhere. 
  They 
  are 
  found 
  upon 
  the 
  ridges 
  and, 
  at 
  the 
  posterior 
  

   end 
  of 
  the 
  body, 
  upon 
  the 
  squarish 
  blocks 
  of 
  skin 
  into 
  which 
  the 
  

   ridges 
  are 
  broken. 
  The 
  skin 
  and 
  body 
  wall 
  are 
  thick 
  and 
  tough 
  in 
  

   most 
  individuals. 
  

  

  