Note 79 — Chapter IV

Charles Brongniart has lately described a fossil Insect from the Coal Measures of Commentry, which he names Corydaloides Scudderi, and refers to the Pseudo-Neuroptera. In this Insect every ring of the abdomen carries laminæ, upon which the ramified tracheæ can still be made out by the naked eye. Stigmata co-existed with these tracheal gills. (Bull. Soc. Sci. Nat. de Rouen, 1885.)

Some Crustacea are furnished with respiratory leaflets, curiously like those of Tracheates, with which, however, they have no genetic connection. In Isopod Crustacea the exopodites of the anterior abdominal segments often form opercula, which protect the succeeding limbs. In the terrestrial Isopods, Porcellio and Armadillo, these opercula contain ramified air-tubes, which open externally, and much resemble tracheæ. The anterior abdominal appendages of Tylus are provided with air-chambers, each lodging brush-like bundles of air-tubes, which open to the outer air. Lamellæ, projecting inwards from the sides of the abdominal segments, incompletely cover in the hinder part of the ventral surface of the abdomen, and protect the modified appendages. (Milne Edwards, Hist. Nat. des Crustacés, Vol. III.)