Diagram showing the anterior four-fifths of the eyeball.

Human Eye

Diagram showing the anterior four-fifths of the eyeball.

"Liphistius desultor. Lateral view. I to VI, Appendages of the prosoma cut off at the base. o, Ocular tubercle. praegen, The prae-genital somite. 1 and 2, Sternites of the first and second opisthosomatic somites. 3 and 4, Appendages of the third and fourth opisthosomatic somites, which are the spinning organs, and in this genus occupy their primitive position instead of migrating to the anal region as in other spiders. 5, Tergite of the fifth opisthosomatic somite. II, Eleventh opisthosomatic somite; an, Anus." — The Encyclopedia Britannica, 1910

Liphistius Desultor

"Liphistius desultor. Lateral view. I to VI, Appendages of the prosoma cut off at the base. o, Ocular…