﻿562 
  On 
  a 
  new 
  Genus 
  of 
  Isopoda 
  from 
  Algiers. 
  

  

  tlioracic 
  segments. 
  Ceplialon 
  richly 
  tuberculated 
  and 
  par- 
  

   tially 
  flanked 
  by 
  the 
  lateral 
  plates 
  of 
  the 
  first 
  segment 
  of 
  the 
  

   niesosome 
  ; 
  lateral 
  lobes 
  well 
  developed 
  and 
  turned 
  upwards, 
  

   median 
  lobes 
  absent. 
  Eyes 
  large, 
  subdorsal. 
  Antennulse 
  

   (fig. 
  2) 
  small, 
  3-jointed. 
  Antennaj 
  (fig. 
  3) 
  long, 
  fifth 
  joint 
  

   largest, 
  the 
  flagelluni 
  articulating 
  with 
  the 
  peduncle 
  in 
  deep 
  

   cavity, 
  exceedingly 
  mobile 
  ; 
  flagellnni 
  2-jointed, 
  with 
  a 
  

   smaller 
  2-jointed 
  terminal 
  portion. 
  Mandibles 
  (figs. 
  4 
  & 
  o) 
  

   stout, 
  with 
  four 
  teeth 
  and 
  two 
  tufts 
  of 
  seta?. 
  First 
  niaxillse 
  

   (fig. 
  G), 
  outer 
  lobe 
  with 
  three 
  large 
  and 
  four 
  smaller 
  in- 
  

   curved 
  spines, 
  inner 
  lobe 
  (fig. 
  7) 
  with 
  two 
  setaceous 
  spines 
  

   on 
  the 
  inner 
  border. 
  Second 
  maxilla? 
  thin 
  and 
  plate-like. 
  

   The 
  segments 
  of 
  the 
  mesosome 
  1-3 
  richly 
  tuberculated 
  

   with 
  large 
  processes, 
  remaining 
  segments 
  with 
  finer 
  and 
  

   much 
  smaller 
  tubercles; 
  lateral 
  plates 
  not 
  expanded, 
  pos- 
  

   terior 
  angle 
  overlapping 
  next 
  segment. 
  Maxillipedes 
  

   (fig. 
  8) 
  large 
  and 
  well 
  developed 
  ; 
  the 
  outer 
  lol)e 
  termi- 
  

   nates 
  in 
  three 
  small 
  spines 
  and 
  a 
  large 
  multispinous 
  

   process 
  ; 
  inner 
  lobe 
  distally 
  flattened 
  with 
  three 
  small 
  

   marginal 
  spines. 
  The 
  ventral 
  surface 
  of 
  the 
  body 
  is 
  raised 
  

   and 
  fringed 
  outwardly 
  with 
  small 
  spines. 
  Thoracic 
  ap- 
  

   pendages 
  (fig. 
  9) 
  large 
  and 
  chaiacterized 
  by 
  a 
  series 
  of 
  

   short 
  blunt 
  marginal 
  spines, 
  general 
  surface 
  of 
  the 
  segments 
  

   covered 
  with 
  small 
  pointed 
  spines. 
  On 
  the 
  second 
  appendage, 
  

   at 
  the 
  distal 
  end 
  and 
  outer 
  side 
  of 
  the 
  proto])odite 
  is 
  a 
  small 
  

   pit-like 
  depression 
  lined 
  with 
  minute 
  spines 
  (fig. 
  9, 
  p.d.). 
  

   Abdominal 
  appendages 
  (figs. 
  lOa-h), 
  first 
  small 
  (probably 
  

   degenerate), 
  second 
  (tig. 
  10 
  6), 
  exopodite 
  triangular 
  in 
  shape, 
  

   with 
  knob-like 
  thickening 
  on 
  the 
  outer 
  lower 
  border, 
  endo- 
  

   jiodite 
  small. 
  Uropoda 
  (fig. 
  11) 
  well 
  developed, 
  basal 
  })lato 
  

   Jaige, 
  exopodite 
  broad 
  and 
  blunt, 
  enda)iodite 
  attached 
  above 
  

   and 
  on 
  the 
  inner 
  border, 
  slender, 
  and 
  shorter 
  than 
  exopodite. 
  

   Telson 
  small 
  and 
  triangular. 
  

  

  Length 
  22 
  mm. 
  

  

  Colour 
  (in 
  alcohol) 
  creamy 
  brown, 
  with 
  slaty-grey 
  abdomen. 
  

  

  Hah. 
  Algeria, 
  1873 
  (/. 
  W. 
  Clark). 
  

  

  Type. 
  In 
  the 
  University 
  Museum 
  of 
  Zoology, 
  Cambridge. 
  

  

  In 
  the 
  form 
  of 
  the 
  antennas, 
  first 
  maxillae, 
  telson, 
  and 
  

   uropoda 
  the 
  genus 
  shows 
  a 
  relationship 
  with 
  the 
  genus 
  

   NiaryihicJt, 
  Budde-Lund, 
  but 
  differs 
  from 
  the 
  known 
  members 
  

   of 
  that 
  genus 
  in 
  all 
  other 
  features. 
  The 
  peculiar 
  form 
  of 
  the 
  

   lateral 
  lobes 
  of 
  the 
  head 
  at 
  once 
  separate 
  this 
  genus 
  from 
  

   any 
  other 
  I 
  kiiOAV 
  of. 
  Instead 
  of 
  being 
  flat-like 
  extensions 
  

   of 
  the 
  head 
  disposed 
  horizontally, 
  they 
  are 
  turned 
  vertically 
  

   inwards. 
  There 
  is 
  no 
  trace 
  of 
  any 
  median 
  lobe, 
  the 
  front 
  ot 
  

   the 
  head 
  gradually 
  slo2">ing 
  over 
  on 
  to 
  the 
  epistoma. 
  

  

  