This is a collection of bits and pieces (including “male genital armature” in 1s and 1t) of Pseudotremia cavernarum, the cave millipede. Yes, the researchers got up close and personal with them in Wyandotte Cave in Indiana.
The image is Plate VI from The Cave Fauna of North America, with remarks on the anatomy of the brain and origin of the blind species by A.S. Packard, found in the Biodiversity Heritage Library.
Packard’s name is under the illustration, but so is James Henry Emerton’s. He was apparently a young natural historian who became noted as a scientist for his ability as an artist, providing all sorts of illustrations and also creating the original molds for the giant squid and octopus now on display at in Harvard’s Museum of Comparative Zoology and in the National Museum of Natural History at Washington. He displayed watercolors at art shows and sifted through leaf litter in New England woods to find tiny spider body parts to draw. Seems like a fun fellow.