﻿230 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.96 
  

  

  Type. 
  — 
  Formerly 
  in 
  St. 
  Petersburg 
  Museum; 
  collected 
  by 
  H. 
  

   Mertens. 
  

  

  Type 
  locality. 
  — 
  Sitka, 
  Alaska. 
  

  

  Genus 
  THALASSEMA 
  Lamarck 
  

  

  Thalassema 
  Lamarck, 
  1801, 
  p. 
  328 
  (type, 
  Lumbricxis 
  thalassema 
  ' 
  Pallas, 
  1771, 
  

   Spicilegia 
  Zoologica, 
  fasc. 
  10, 
  p. 
  8, 
  pi. 
  1, 
  fig. 
  6). 
  

  

  Diagnosis. 
  — 
  Echiuridae 
  with 
  a 
  well-developed 
  proboscis 
  but 
  \\dthout 
  

   anal 
  bristles 
  and 
  without 
  specialized 
  bands 
  in 
  the 
  longitudinal 
  layer 
  

   of 
  body 
  muscles; 
  inner 
  oblique 
  layer 
  smooth, 
  except 
  sometimes 
  for 
  a 
  

   short 
  distance 
  at 
  anterior 
  end 
  of 
  body 
  ; 
  anterior 
  nephridia 
  (gonothecae) 
  

   one 
  or 
  two 
  pairs, 
  the 
  internal 
  ciliated 
  funnel 
  (nephrostome) 
  without 
  

   spiral 
  lobes. 
  ^ 
  

  

  THALASSEMA 
  STEINBECKI, 
  new 
  species 
  

  

  Figure 
  11 
  

  

  Diagnosis. 
  — 
  Small, 
  slightly 
  translucent, 
  the 
  proboscis 
  as 
  long 
  as 
  

   body, 
  broad 
  proximally, 
  ribbonlike 
  distally; 
  nephridia, 
  two 
  pairs, 
  the 
  

   cUiated 
  funnel 
  with 
  simple 
  subcircular 
  opening 
  lacking 
  any 
  trace 
  of 
  

   sphal 
  lips; 
  interbasal 
  muscle 
  of 
  setae 
  well 
  developed, 
  strong, 
  passing 
  

   through 
  loop 
  of 
  dorsoventral 
  blood 
  vessel; 
  siphon 
  beginning 
  a 
  short 
  

   distance 
  from 
  vascular 
  ring; 
  precloacal 
  intestinal 
  coecum; 
  intestinal 
  

   mesenteries 
  including 
  conspicuous 
  subfusiform 
  fleshy 
  masses; 
  anal 
  

   vesicles 
  as 
  long 
  as 
  contracted 
  body, 
  covered 
  with 
  numerous 
  tiny 
  

   ciliated 
  funnels. 
  Length 
  of 
  body 
  12 
  mm.; 
  of 
  proboscis, 
  12 
  mm. 
  

  

  Description. 
  — 
  The 
  skin 
  is 
  coarsely 
  verrucose 
  for 
  a 
  short 
  distance 
  

   back 
  of 
  proboscis 
  and 
  on 
  terminal 
  tliird 
  of 
  body; 
  elsewhere 
  the 
  verrucae 
  

  

  ' 
  Thalassema 
  was 
  first 
  used 
  in 
  a 
  generic 
  sense 
  by 
  Lamarck. 
  Although 
  Pallas 
  (Spicilegia, 
  1771) 
  mentions 
  « 
  

   the 
  name 
  Thalassema 
  as 
  used 
  by 
  Joseph 
  Gaertner, 
  he 
  names 
  the 
  animal 
  Lumbricus 
  thalassema, 
  which 
  appears 
  

   to 
  be 
  the 
  first 
  valid 
  binomial 
  referring 
  to 
  the 
  species 
  generally 
  known 
  as 
  Thalassema 
  neptuni 
  Gaertner. 
  The 
  

   latter 
  is 
  in 
  effect 
  a 
  manuscript 
  name. 
  Neither 
  Shipley 
  (1899, 
  p. 
  351) 
  nor 
  Wharton 
  (1913, 
  p. 
  265), 
  who 
  have 
  

   offered 
  revisions 
  of 
  Thalassema, 
  gives 
  any 
  reference 
  for 
  the 
  combination 
  Thalassema 
  neptuni. 
  Quatrefages 
  

   (1865, 
  vol. 
  2, 
  p. 
  595) 
  cites 
  "Thalassema 
  Neptuni 
  Gaertner, 
  citfi 
  par 
  Pallas, 
  Spicilegia 
  Zoologica, 
  fasc. 
  10, 
  p. 
  8, 
  

   pi. 
  1, 
  fig. 
  6." 
  Forbes, 
  1841, 
  in 
  his 
  "History 
  of 
  British 
  Starfishes 
  and 
  Other 
  Animals 
  of 
  the 
  Class 
  Echino- 
  

   dermata," 
  gives 
  a 
  good 
  account 
  of 
  the 
  habits 
  of 
  "Gaertner's 
  spoon-worm, 
  Thalassema 
  Neptuni 
  Gaertner." 
  

   The 
  first 
  item 
  in 
  his 
  list 
  of 
  references 
  is 
  Lumbricus 
  Thalassema 
  Pallas. 
  

  

  The 
  derivation 
  of 
  the 
  word 
  seems 
  to 
  be 
  thnlassos 
  (sea) 
  + 
  ema 
  (dart). 
  

  

  8 
  Shipley 
  (1899, 
  p. 
  351) 
  in 
  his 
  revision 
  of 
  Thalassema 
  is 
  in 
  error 
  in 
  the 
  statement 
  that 
  the 
  nephridia 
  have 
  

   their 
  internal 
  openings 
  gpirally 
  twisted. 
  Lankester 
  (1881, 
  p. 
  355) 
  writes 
  that 
  they 
  are 
  semicircular 
  and 
  

   contrasts 
  them 
  with 
  the 
  spiral 
  sort 
  found 
  in 
  T. 
  moebii, 
  as 
  figured 
  in 
  Greef's 
  "Die 
  Echiuren" 
  (1879, 
  pi. 
  8, 
  fig. 
  69). 
  

  

  Figure 
  11.— 
  Thalassema 
  steinhecki, 
  new 
  species: 
  A, 
  The 
  type, 
  X 
  14, 
  showing 
  arrangement 
  of 
  

   organs; 
  the 
  greater 
  part 
  of 
  the 
  intestine 
  has 
  been 
  omitted 
  and 
  the 
  foregut 
  has 
  been 
  strongly 
  

   bent 
  to 
  right 
  in 
  order 
  to 
  uncover 
  the 
  nephridia. 
  B, 
  A 
  seta, 
  X 
  20, 
  from 
  a 
  specimen 
  taken 
  

   in 
  165 
  fathoms 
  off 
  San 
  Francisquito 
  Bay, 
  Baja 
  California; 
  above, 
  the 
  hook, 
  further 
  en- 
  

   larged. 
  C, 
  Ventral 
  view 
  of 
  the 
  type, 
  X 
  4. 
  {AV, 
  Anal 
  vesicle; 
  B^-B*, 
  dorsal, 
  ring, 
  neuro- 
  

   intestinal, 
  and 
  ventral 
  vessels; 
  C, 
  stomach; 
  CG, 
  ciliated 
  furrow 
  of 
  intestine; 
  CI, 
  cloaca; 
  

   G, 
  gizzard; 
  /, 
  intestine; 
  IC, 
  intestinal 
  coecum; 
  Me, 
  mesenterial 
  bodies; 
  MI, 
  interbasal 
  

   muscle 
  of 
  setae; 
  N, 
  nephridia; 
  NC, 
  nerve 
  cord; 
  0, 
  esophagus; 
  P, 
  pharynx; 
  S, 
  seta; 
  Sil, 
  

   anterior 
  end 
  of 
  siphon.) 
  

  

  