Figure 1 in A zoologist's perspective on Robert Hooke's Micrographia (1665) studies of marine and terrestrial invertebrates, and his contemplations on invertebrate "generation" and mutability

Figure 1. (A) Spongin fibre skeleton of a marine sponge (phylum Porifera) of indeterminate genus or species, but most likely either Spongia or Hippospongia (Family Spongiidae: Order Dictyoceratida: Class Demospongiae). (B, C) The skeletal remains of a colony of Flustra foliacea L. (Phylum Ectoprocta), a colonial marine animal. Note Hooke's use of a scale line in (C). Engravings reproduced by permission of the Rare Book and Manuscript Library of the University of Pennsylvania.