
 
        
         
		EMYS CONCENTRICA. 
 first, and  one  of the most peculiar,  is  distinguished  by very deep  furrows  on  
 all the dorsal plates,  by the  whole  margin  being  revolute,  and  by the  spots  
 on the sternal plates assuming  a  radiating  instead  of a concentric form.  The  
 second variety (Plate b.)  has  the  vertical  plate,  the  greater part of the  neck,  
 the feet and tail,  as well as the  shell, of  a  black  colour,  the  anterior  part  of  
 the neck and the sides of the head only approaching  the  usual colours of  the  
 species.  In  the  third  variety ( Plate  e.) the skin  is  of a  brightish  and  pale  
 green  colour, with  black lines on the head  and neck, and black spots and  dots  
 on the rest of the  body and  limbs,  the  shell being nearly black.  This is the  
 only variety which  I  have seen  in which the vertical plate has been of more  
 than one colour ;  in all others it is of an  uniform  black  or greenish  hue,  and  
 very distinct from the rest of the head.  The  fourth  variety I was tempted to  
 consider as a distinct species when  I  had seen but few specimens;  I  had  even  
 given it  the appellation  E.  livida*; but  I  have  long  been  convinced that  this  
 was an  error.  It  is  of  an  uniform  livid  green  colour,  with the dorsal  scuta  
 very slightly furrowed.  The sternum is equally without  markings, and  of  a  
 dull  greenish  yellow  colour.  A  fifth  variety,  which  attains  to  a very large  
 size,  has the dorsal platés of  a  rufous  or  reddish  brown  colour,  with darker  
 concentric lines, and the sternum of a light chestnut. 
 The usual colours of the species are as follow.  The  head  is greenish with  
 numerous black dots ;  the vertical plate, which is of the form of an elongated  
 lozenge, is either green or  black ;  the eyes  are  bright  yellow,  with the pupil  
 and many minute dots black ;  the  neck,  the  feet, the tail, and the skin of the  
 thighs are all greenish with irregular  black  dots, most of which are angular ;  
 the  dorsal plates are of  a  dull  olive,  with  brown  concentric  rings,  and  some  
 other  markings  of the  same  colour  are  occasionally  found,  especially on  the'  
 vertebral plates;  the  sternum  is  yellowish, with  a  light  brown  line  running  
 within  the margin of each  plate,  usually  formed  of irregular elongated  spots*  
 though in some  they are  quite  continuous;  within  this line  are various spots  
 and irregular markings of the same colour;  and  thé ; areola of each plate is in  
 most cases  orange,  gradually fading  oif into  the  light  ground  colour of the  
 Sternum. 
 *  Vide Gray, Syn, Rept. p. 27. 
 EMYS  CONCENTRICA. 
 The  account  of the  habitat  of  this  species  given  by  the  Prince  of Musi-  
 gnano, is that it is  found in great  abundance  in  the United  States  from New  
 York as far south  as  the  Floridas,  particularly in  Maryland  and Virginia,  as  
 well as in the West  Indies.  It delights in the neighbourhood of such marshes  
 as aré alternately overflowed by salt and fresh water; from which circumstance  
 it is, as  I am informed,  called the Saltwater Terrapin.  Its flesh is esteemed  a  
 most delicious food;  and  my friend  Dr. Harlan, of Philadelphia,  informs  me  
 that it is so  much sought for  on  this  account,  that it has almost wholly disappeared  
 for a considerable  distance  around  that  city.  It is considered as  particularly  
 nourishing and easy of digestion for invalids. 
 I  have  received  many  of  this  species  from  different  parts  of  the  United  
 States, and  have  had  during  the  last winter  six  of them  hibernating  at  the  
 bottom of a small  pond in  the neighbourhood of London, the whole of which  
 were kindly sent me about twelve months since by Mv.  IMonefeldt of Charlestown, 
  South Carolina.  They remained in perfect  health  and  activity during  
 the summer and early part of the autumn, seeking their final winters retreat at  
 the bottom of the water at the latter end  of October.  Two of these died at the  
 commencement  of the  spring:  the  remaining  four  are  now  (June  1834)  in  
 perfect  health.  Some  individuals  which  hibernated  in  the  same  situation  
 during  a  former winter,  died  in the spring;  but I doubt not  that with  care  
 they  may  be  made  to  bear  this  climate,  and  probably  may be  easily  naturalized  
 in  the  South  of Europe.  The  Prince  of  Musignano  has  thus  expressed  
 this  expectation:  “Ho cercato d’introduirle fra noi, e spero tuttora  di  
 riuscirvi. ’ 
 It was in an individual of this  species that I ascertained the  fact that a perfect  
 new horny plate may be formed  under  the  old  one,  which  it gradually  
 displaces.  I found that one of the anterior costal  plates  was loosening at the  
 edges, and by watching  it  from  time  to  time,  observed that it became more  
 and  more  detached,  until  it  fell  off quite whole,  and  apparently  uninjured.  
 The new plate was exactly like the old one,  and  in  a few days it could  not be  
 perceived that any change had taken place.