Mark, E.L. 1877 Beiträge zur Anatomie und Histologie der Pflanzenläuse, insbesondere der Cocciden. [Contribution to the anatomy and histology of insect pests, especially Coccidae.]. Archiv für Mikroskopische Anatomie 13: 31-81.

Notes: The scale insect digestive tract is described with its appendages. Species mentioned include Aspidiotus nerii, Chermes abietis, Chionaspis aspidistrae, C. vaccinii, Coccus adonium (adonidum?), C. ulmi and Lecanium hesperidum.