Immutable queue implementation in Scala

Question

I created a queue in which we can perform Enqueue, Dequeue and Traversing in Scala.

class Queue[+A](list:List[A]) {
  def enqueue[B>:A](x:B):Queue[B]= new Queue[B](list :+ x)
  def dequeue[B>:A]:Queue[B] = new Queue[B](list.tail)
  def head = list.head
  def tail = list.tail
}

Please review this code and make suggestions.