SyncListInt vs SyncList TO

I am trying to sync List of Vector3. InBetween ,

According to this documentation : http://docs.unity3d.com/ScriptReference/Networking.SyncList_1.SyncListChanged.html

An list of interger is declared as

 public SyncListInt myInt =  new SyncListInt() ;

Now , according to this Documentation , http://docs.unity3d.com/ScriptReference/Networking.SyncList_1.html

 // Therefore i tried declaring it as
 public SyncList<Vector3> myVector ;
 This worked perfectly but to use it i had to create new instance as we created for SyncListInt , so that would be 
 public SyncList<Vector3> myVector = new SyncList<Vector3>() ;
 //This code throws an error 

 error CS0144: Cannot create an instance of the abstract class or interface `UnityEngine.Networking.SyncList<UnityEngine.Vector3>'

Anyidea for declaring SyncList , well i have already seen the SyncListStruct but i need SyncList