"Entosternum of one of the mygalomorphous spiders; ventral surface. Ph.N., pharyngeal notch. The posterior median process with its repetition of triangular segments closely resembles the same process in Limulus." — The Encyclopedia Britannica, 1910

Entosternum

"Entosternum of one of the mygalomorphous spiders; ventral surface. Ph.N., pharyngeal notch. The posterior…

"Ventral view of a male mygalomorphous spider. I to VI, The six pairs of prosomatic appendages. a, Copulatory apparatus of the second appendage. a, Copulatory apparatus of the second appendage. b, Process of the fifth joint of the third appendage. M, Mouth. pro, Prosternite of the prosoma. mes, Mesosternite of the prosoma: observe the contact of the coxae of the sixth pair of limbs behind it; compare Liphistius where this does not occus. stg, Lung aperture. gn, Genital aperture. a, Anus with a pair of backwardly migrated spinning appendages on each side of it; compare the position of these appendages in Liphistius." — The Encyclopedia Britannica, 1910

Spider

"Ventral view of a male mygalomorphous spider. I to VI, The six pairs of prosomatic appendages. a, Copulatory…