JsonFX polymorphic deserialization

I know this isn't unity specific, but JsonFX seems to be the most often recommended Json library for Unity, so I thought you guys might be familiar with this (and it is for a Unity project).

Does anybody know how to properly serialize and deserialize a collection of polymorphic objects using JsonFX? My serializer works, but the object that I'm serializing contains a list of polymorphic entities, and they're all deserialized as their base type and not their actual type.

Here's my serialization code:

 public static string Serialize(System.Object obj)
 {
     StringBuilder builder = new StringBuilder();
     using (TextWriter textWriter = new StringWriter(builder))
     {
         JsonWriter writer = new JsonWriter(textWriter);
         writer.Write(obj);
 
         return builder.ToString();
     }
 }
 
 public static T Deserialize<T>(string json)
 {
     using (TextReader textReader = new StringReader(json))
     {
         var jsonReader = new JsonReader(textReader);
         return jsonReader.Deserialize<T>();
     }
 }

As you can see it's pretty straightforward. I'm also not decorating my classes with any attributes or anything special to make them serializable. Besides the polymorphic problem, it all just seems to be working properly.

So how can I get my polymorphic types to deserialize properly?.

Thanks.