In 1832, Gabriel Bibron (1806–1848), who became his assistant, was given the task of describing the species for an expanded version of Zoologie analytique, while Nicolaus Michael Oppel (1782–1820) assisted him with a revised higher-order systematics.
En 1832 o seu axudante Gabriel Bibron (1806-1848), asumiu a tarefa de describir as especies para unha nova versión estendida de Zoologie analytique, mentres que Nicolaus Michael Oppel (1782-1820) o axudou cunha revisión da sistemática.