The single species in this genus has only recently been transfered to the Tit family. It was once considered to belong to the Corvidae but molecular and osteological testing has now indicated that it belongs to the Paridae.
... Naturphilosophie und die Bearbeitung derselben durch Vera (1868)
Erläuterungen zu Hegels Encyklopädie der philosophischen Wissenschaften (1871).
Two other of his works ...