On the structure of the respiratory organs of the terrestrial Isopoda

Terrestrial isopuds present problems in respiration because of their change of habitat. With organs of respiration which are homologous with the tbranchire of Asellus and other aquatic isopods, they live on land and breathe air.
They are found in very varied situations; some require very wet conditions, others can live in comparatively dry places.
In this communication I propose to describe the interesting anatomical features of the respiratory organs of certain species.
In the species treated of, and in the Oniscaddea generally, five pairs of ahdominal app·endages take some part in respiration. I propose to describe these appendages in the female forms only. There are no differences in the essential points of histology and physiology between the male and female pleopods, and the fact that, in the male, reproductive processes are associated with the 1st and 2nd p1eopods, brings in an unnecessary complication.