Note 17 — Blind Trilobites.
Reading edition
Packard, Development of Limulus polyphemus. Memoirs Boston Soc. Nat. H. vol. II, pl. V, fig. 25. Nothing is said about the exterior structure of the eyes.
Dohrn, Zur Embryologie and Morphologie des Limulus Polyphemus. Jenaische Zeitschrift 1871. A very good figure (pl. XIV, f. 4) shows clearly the two parts of the eyes, the interior one being larger.
Kingsley also (Devel. of Limulus, Journal of Morphology, vol. 7, 1892, pl. VI, fig. 34) has in the last larval stage the suture and the eye in two parts, of which one is white lying inside the suture and the eye proper, black, outside.