Madreporites on sea stars
”The madreporite is a lightcolored calcerous opening used to filter water into the water vascular system of echinoderms. It acts like a pressure-equalizing valve. […] Close up, it is visibly structured, resembling a “madrepore” (stone coral, Scleractinia) colony.” — Wikipedia
Image 1: Madreporites, from Pierce and Maugel’s 1987 Illustrated Invertebrate Anatomy (via “How Starfish Move”)
Image 2: Madreporite of Henricia pumila:”The madreporite is creamy colored as in the type specimen. Notice the papulae extended among the pseudopaxillae.” (Source)
I don’t know what to call this pattern, but I like it!
Image 1: “The Maze” by Debralee Wiseberg (link and another gallery)… I think it’s corroded metal?
Image 2: 2,2-(Bipyridine)(Naphthalene)-fusion melt (25x)
Herb Comess. Honorable Mention, 1994 Nikon Small World Photomicrography Competition (link)