"Three stages in the development of Apus. fs, frontal sensory organ; L, digestive gland; s, carapace; 1-4, cephalic appendages; I-XIII, body segments and appendages." -Parker, 1900

Apus Stages

"Three stages in the development of Apus. fs, frontal sensory organ; L, digestive gland; s, carapace;…