1888, Thomas Henry Huxley, A Manual of the Anatomy of Invertebrated Animals[1]:
On the other hand, in the development of a mesoblast which undergoes division into segments, the Leeches exhibit the fundamental character of all such segmented Invertebrates as the chaetophorous Annelida and the Arthropoda.
While chaetophorous characters are, evolutionally, of recent origin, yet the arrangement of the macrochaetae of the head, thorax, abdomen, and legs becomes highly important in separating tribes, genera, and species.
1950, Commonwealth Scientific and Industrial Research Organization (Australia), Australian journal of marine and freshwater research[3]:
In the marine zone a preponderance of the soft-bodied chaetophorous forms is encountered.
