Note 312 — Chapter XV · ARACHNIDA EMBOLOBRANCHIATA (CONTINUED)—ARANEAE (CONTINUED)—CLASSIFICATION
Reading edition
According to Bertkau (in a letter to Simon, cited in Hist. Nat. des Ar. i. p. 327), two pairs of linear stigmata under the anterior part of the abdomen lead, to pulmonary sacs, but to tracheae.