I'm trying to deserialize entire document that contains polymorphic collection to dynamic object.
And I expect that my collection will contain dynamic objects but I've got concrete types.
I've created pull request with fix and unit test.

Example data:
var json = "{ \"Shapes\" : [

{ \"_t\" : \"Circle\", \"Radius\" : 5 }

,

{ \"_t\" : \"Square\", \"Side\" : 3 }

] }";

Current behavior:
typeof(Circle) == obj.Shapes[0].GetType()
typeof(Square) == obj.Shapes[1].GetType()

Expected:
typeof(ExpandoObject) == obj.Shapes[0].GetType()
typeof(ExpandoObject) == obj.Shapes[1].GetType()