With plural agreement. A former order of barnacles which bore into a variety of calcareous material, comprising typically small, shell-less forms having several pairs of cirri towards the end of the thorax.
Abdominalia were renamed Acrothoracica in 1905.
Mid 19th century; earliest use found in Charles Darwin (1809–1882), naturalist, geologist, and originator of the theory of natural selection. From scientific Latin Abdominalia from post-classical Latin abdominalis + -ia.