The reason is because your collection is expecting an array of models as it's response but your service is returning the array under entries. From the documentation
parse is called by Backbone whenever a collection's models are returned by the server, in fetch. The function is passed the raw response object, and should return the array of model attributes to be added to the collection.
To work around that you can simply override your parse method to return the array of models.
For example:
app.ContactList = Backbone.Collection.extend({
//...
parse: function (response) {
return response.entries;
}
})