﻿NO. 
  1971. 
  NEW 
  SPECIES 
  OF 
  CRABS— 
  RATHBUN. 
  619 
  

  

  is 
  scarcely 
  bilobed; 
  the 
  ridge 
  on 
  the 
  palm 
  is 
  strong 
  and 
  the 
  upper 
  

   edge 
  marginate, 
  both 
  in 
  undeveloped 
  males 
  as 
  well 
  as 
  in 
  females. 
  

  

  The 
  species 
  differs 
  from 
  M. 
  pacificus 
  Dana 
  ^ 
  in 
  its 
  greater 
  hairi- 
  

   ness; 
  in 
  the 
  upper 
  margin 
  of 
  the 
  orbit 
  trending 
  forward 
  at 
  its 
  outer 
  

   end 
  instead 
  of 
  backward 
  ; 
  in 
  the 
  carapace 
  being 
  more 
  quadrate 
  in 
  

   shape 
  and 
  -without 
  sharp 
  lines 
  of 
  granules 
  on 
  the 
  branchial 
  region; 
  

   in 
  the 
  front 
  having 
  a 
  narrow 
  rim 
  of 
  even 
  width 
  throughout, 
  while 
  in 
  

   pacificus 
  the 
  rim 
  widens 
  along 
  the 
  sides 
  from 
  above 
  downward, 
  so 
  

   that 
  while 
  the 
  front 
  in 
  its 
  entirety 
  is 
  constricted, 
  the 
  depressed 
  or 
  

   middle 
  portion 
  of 
  it 
  is 
  not 
  constricted 
  but 
  narrows 
  downward; 
  the 
  

   tooth 
  on 
  the 
  movable 
  finger 
  plays 
  into 
  a 
  cavity 
  in 
  the 
  immovable 
  

   finger, 
  while 
  in 
  pacificus 
  it 
  moves 
  against 
  or 
  toward 
  an 
  elevation 
  on 
  

   the 
  immovable 
  finger. 
  

  

  De 
  Man 
  in 
  1902 
  ^ 
  contrasts 
  a 
  female 
  without 
  locahty 
  label, 
  which 
  

   he 
  described 
  in 
  1890,-^ 
  with 
  a 
  female 
  from 
  Tobelo, 
  Halmahera, 
  and 
  

   thinks 
  that 
  the 
  former 
  may 
  not 
  be 
  M. 
  pacificus, 
  as 
  he 
  thought 
  in 
  

   1890, 
  because 
  Dana's 
  figure 
  does 
  not 
  show 
  the 
  granular 
  lines 
  on 
  the 
  

   carapace. 
  De 
  Man 
  further 
  thinks 
  that 
  the 
  Halmahera 
  specimen 
  

   may 
  be 
  pacificus 
  and 
  the 
  1890 
  specimen 
  hicarinatus 
  Heller. 
  

  

  The 
  1890 
  specimen 
  is 
  the 
  same 
  species, 
  I 
  think, 
  as 
  the 
  specimens 
  

   called 
  pacificus 
  in 
  the 
  present 
  paper, 
  while 
  the 
  Halmahera 
  specimen 
  

   (MacropJithalmus, 
  sp., 
  de 
  Man) 
  is 
  the 
  one 
  described 
  here 
  as 
  crinitus. 
  

   The 
  reasons 
  why 
  I 
  attach 
  the 
  name 
  pacificus 
  to 
  the 
  former 
  instead 
  

   of 
  the 
  latter 
  are 
  (1) 
  the 
  shape 
  of 
  the 
  carapace; 
  (2) 
  the 
  depressed 
  

   portion 
  of 
  the 
  front 
  narrows 
  forward, 
  as 
  it 
  appears 
  to 
  in 
  Dana's 
  

   figure; 
  (3) 
  the 
  shape 
  and 
  hairiness 
  of 
  the 
  legs 
  correspond; 
  (4) 
  the 
  

   spine 
  on 
  the 
  meropodites 
  is 
  sharp 
  and 
  plainly 
  visible, 
  which 
  it 
  is 
  not 
  

   in 
  crinitus. 
  

  

  Dana 
  describes 
  the 
  carapace 
  of 
  pacificus 
  as 
  "naked 
  and 
  smooth" 
  

   and 
  figures 
  no 
  granular 
  lines, 
  but 
  the 
  posterolateral 
  regions 
  are 
  

   represented 
  as 
  pubescent 
  in 
  the 
  illustration. 
  His 
  type 
  was 
  an 
  imma- 
  

   ture 
  male 
  of 
  small 
  size; 
  perhaps 
  the 
  lines 
  were 
  inconspicuous. 
  

  

  Heller's 
  figure 
  of 
  M. 
  hicarinatus 
  * 
  is 
  too 
  unlike 
  the 
  species 
  under 
  

   consideration 
  to 
  be 
  united 
  with 
  either. 
  

  

  1 
  U. 
  S. 
  Expl. 
  Exp., 
  vol. 
  13, 
  Crust., 
  pt. 
  1, 
  1852, 
  p. 
  314; 
  atlas, 
  1855, 
  pi. 
  19, 
  fig.4 
  a-c. 
  

  

  2 
  Abh. 
  Senckenb. 
  naturf. 
  Ges., 
  vol. 
  25, 
  pp. 
  

  

  3 
  Notes 
  Leyden 
  Mus., 
  vol. 
  12, 
  p. 
  79. 
  

   * 
  Reise 
  Novara, 
  Crust., 
  1865, 
  pi. 
  4, 
  fig. 
  2. 
  

  

  