﻿166 
  

  

  E. 
  RAY 
  LANKESTER. 
  

  

  descent 
  known 
  as 
  the 
  classes 
  Diplopoda, 
  Crnstacea, 
  Chilo- 
  

   poda, 
  and 
  Hexapoda. 
  

  

  Fig. 
  1. 
  — 
  Entosternum, 
  entosternite 
  or 
  plastron 
  of 
  Limulus 
  

   pol.yphemus,Liiin. 
  Dorsal 
  surface. 
  LAP, 
  left 
  anterior 
  process; 
  

   RAP, 
  rislit 
  anterior 
  process 
  ; 
  PhN, 
  pliaryn<?eal 
  notcli; 
  ALR, 
  anterior 
  

   lateral 
  rod 
  or 
  tendon 
  ; 
  PLR, 
  posterior 
  lateral 
  rod 
  or 
  tendon; 
  PLP, 
  

   posterior 
  lateral 
  process. 
  Natural 
  size. 
  (From 
  Lankester, 
  'Q. 
  J. 
  

   Micr. 
  Sci./ 
  N.S., 
  vol. 
  xxiv, 
  1884.) 
  

  

  PLK'^ 
  

  

  Fig. 
  2. 
  — 
  Ventral 
  surface 
  of 
  the 
  entosternum 
  of 
  Limulus 
  poly- 
  

   p 
  hem 
  us, 
  Linn. 
  Letters 
  as 
  in 
  Fig. 
  1 
  with 
  the 
  addition 
  of 
  NF, 
  

   neural 
  fossa 
  protecting 
  the 
  ajrgregated 
  ganglia 
  of 
  the 
  central 
  

   nervous 
  system; 
  PVP, 
  left 
  posterior 
  ventral 
  process; 
  PMP, 
  pos- 
  

   terior 
  median 
  process. 
  Natural 
  size. 
  (From 
  Lankester.) 
  

  

  Limulus 
  an 
  Ai'achnid. 
  — 
  Modern 
  views 
  as 
  to 
  the 
  classifi- 
  

   cation 
  and 
  affinities 
  of 
  the 
  Arachnida 
  have 
  been 
  determined 
  

  

  