Thanks AD for his paper on "Morphology of the Arthropoda" [Rep. BAAS 37 (1867) pt 2: 82], a deeply interesting subject.

Suggests he examine specimens of Scalpellum.

Fritz Müller thinks CD is mistaken, but CD cannot persuade himself he was wrong in his observations on Balanidae [Living Cirripedia 2: 105].

Pleased by CD’s letter; his object was to apply CD’s principles to the reform of zoology. When this is done, it is wonderful to see how improved one’s understanding of the Crustacea (Arthropoda) becomes. Cites examples.