﻿Crustacea 
  of 
  Dominica. 
  17 
  

  

  These 
  specimens 
  appear 
  to 
  differ 
  from 
  Guerin's 
  figure 
  in 
  

   exactly 
  the 
  same 
  respects 
  as 
  did 
  the 
  Cuban 
  specimens 
  re- 
  

   ferred 
  to 
  this 
  species 
  by 
  Dr. 
  von 
  Martens. 
  The 
  femora 
  of 
  

   the 
  third 
  and 
  fourth 
  pairs 
  of 
  pereiopoda, 
  although 
  not 
  con- 
  

   spicuously 
  dilated, 
  are 
  spined 
  beneath, 
  but 
  not 
  so 
  strongly 
  as 
  

   is 
  represented 
  in 
  the 
  aforesaid 
  figure. 
  Further, 
  in 
  one 
  speci- 
  

   men 
  the 
  rostrum 
  is 
  armed 
  beneath 
  with 
  two 
  spines, 
  in 
  the 
  

   other 
  with 
  but 
  one. 
  Guerin's 
  specimens 
  appear 
  to 
  have 
  been 
  

   provided 
  with 
  three. 
  

  

  Family 
  Miersiidse. 
  

  

  Genus 
  XlPHOCARIS. 
  

   Xiphocaris, 
  von 
  Martens, 
  Arch. 
  f. 
  Naturg. 
  1872, 
  p. 
  130. 
  

  

  As 
  Mr. 
  Kingsley 
  has 
  pointed 
  out 
  (Bull. 
  Essex 
  Inst. 
  xiv. 
  

   p. 
  127) 
  the 
  mandible 
  of 
  this 
  genus 
  bears 
  much 
  greater 
  resem- 
  

   blance 
  to 
  that 
  of 
  Atya 
  than 
  to 
  that 
  of 
  Hoplophorus 
  (or 
  Acan- 
  

   thephyra) 
  ; 
  furthermore, 
  since 
  the 
  definition 
  of 
  the 
  group 
  

   Ephyrinas 
  ( 
  = 
  Miersiiii£e) 
  of 
  this 
  author 
  applies 
  in 
  all 
  respects 
  

   to 
  the 
  specimens 
  of 
  Xiphocaris 
  that 
  I 
  have 
  seen, 
  I 
  have 
  

   without 
  hesitation 
  referred 
  the 
  genus 
  to 
  this 
  family, 
  although 
  

   the 
  species 
  of 
  Miersia 
  are 
  unknown 
  to 
  me. 
  

  

  The 
  family 
  appears 
  to 
  occupy 
  a 
  position 
  between 
  some 
  

   such 
  forms 
  as 
  Caridina 
  and 
  Acanthephyra. 
  

  

  Xiphocaris 
  elongata 
  (Gue*rin). 
  

  

  Hippolyte 
  elongata, 
  Guerin, 
  Ramon 
  de 
  la 
  Sagra, 
  Cuba 
  Crust, 
  p. 
  20, 
  

  

  pi. 
  ii. 
  fig. 
  10. 
  

   Hoplophorus 
  americanus, 
  Saussure, 
  Crust, 
  nouv. 
  des 
  Antilles 
  et 
  du 
  

  

  Mexique, 
  p. 
  56, 
  pi. 
  iv. 
  fig. 
  31. 
  

   Xiphocaris 
  elongata, 
  v. 
  Martens, 
  loc. 
  cit. 
  p. 
  140. 
  

  

  Ten 
  specimens 
  (females, 
  without 
  ova) 
  were 
  taken 
  at 
  Laiou. 
  

  

  Average 
  length 
  from 
  base 
  of 
  ophthalmopod 
  to 
  apex 
  of 
  

   telson 
  about 
  28 
  millim. 
  The 
  rostrum 
  of 
  this 
  species, 
  as 
  

   might 
  be 
  expected 
  from 
  its 
  thinness 
  and 
  length, 
  appears 
  to 
  

   be 
  very 
  liable 
  to 
  damage, 
  seeing 
  that 
  in 
  four 
  specimens 
  out 
  

   of 
  the 
  ten 
  this 
  weapon 
  is 
  imperfect 
  — 
  in 
  two 
  cases 
  the 
  apex 
  

   being 
  broken 
  off, 
  in 
  another 
  the 
  anterior 
  half, 
  and 
  in 
  a 
  fourth 
  

   the 
  anterior 
  two 
  thirds. 
  The 
  teeth 
  vary 
  from 
  13 
  to 
  9 
  above 
  

   at 
  the 
  base, 
  6 
  to 
  3 
  above 
  at 
  the 
  apex, 
  and 
  from 
  41 
  to 
  29 
  

   below. 
  In 
  many 
  instances 
  isolated 
  teeth 
  are 
  missing, 
  par- 
  

   ticularly 
  from 
  the 
  lower 
  series. 
  

  

  Ann. 
  & 
  Mag. 
  N. 
  Hist. 
  Ser. 
  6. 
  Vol. 
  iii. 
  2 
  

  

  