﻿38 
  

  

  INTEODUCTION. 
  

  

  so-called 
  centra, 
  the 
  articulary 
  balls 
  of 
  which 
  are 
  

   transversely 
  elliptical, 
  and 
  the 
  neural 
  arch 
  is 
  either 
  

   closed 
  above 
  {vertehrde 
  imbricatim 
  clausse, 
  according 
  to 
  

   the 
  definition 
  of 
  Mertens), 
  as 
  in 
  the 
  Discoglossidse 
  and 
  

   Pelohatidse, 
  or 
  notched 
  between 
  the 
  zygapophyses 
  so 
  

   as 
  to 
  expose 
  the 
  spinal 
  cord 
  between 
  every 
  two 
  verte- 
  

   brse 
  ; 
  the 
  latter 
  type 
  is 
  most 
  marked 
  in 
  Bana, 
  in 
  which. 
  

  

  Fig. 
  15. 
  

  

  Yertebral 
  columns 
  of 
  (a) 
  Discoglossus 
  pictus 
  and 
  (b) 
  Bana 
  esculenta, 
  

  

  upper 
  and 
  lower 
  views. 
  

  

  the 
  lateral 
  openings 
  for 
  the 
  exit 
  of 
  the 
  spinal 
  nerves 
  

   being 
  also 
  of 
  large 
  size, 
  the 
  vertebral 
  column 
  forms 
  an 
  

   open 
  work 
  above 
  and 
  on 
  the 
  sides. 
  Neural 
  spines 
  are 
  

   absent 
  or 
  represented 
  by 
  a 
  low 
  keel, 
  which 
  is 
  much 
  

   prolonged 
  posteriorly 
  in 
  Discoglossus 
  and 
  Felohates. 
  

   The 
  articulation 
  is 
  convexo-concave 
  or 
  opisthocoelous 
  

   in 
  the 
  Discoglossidas, 
  concavo-convex 
  or 
  procoelous 
  in 
  

   the 
  other 
  groups. 
  In 
  those 
  forms 
  in 
  which 
  the 
  verte- 
  

   braB 
  are 
  procoelous 
  the 
  eighth 
  is 
  biconcave; 
  the 
  ninth 
  

   being 
  invariably 
  biconvex. 
  

  

  The 
  first 
  vertebra 
  is 
  devoid 
  of 
  transverse 
  processes 
  

  

  