Note 116 — Chapter XX · CLASS MAMMALIA.

These bones however have no connection with the marsupium, being nearly equally developed in both male and female. They are simply sesamoid bones forming ossifications in the inner tendon of the external oblique muscle, and are developed as supports for the abdominal wall. Very similar structures have been independently developed in various Amphibians, Reptiles and monodelphian Mammals. See W. Leche, Biol. Fören. III. p. 120.