Achæmenian (akemenian)

[L. Achæ menius, a., Achamenes, n., 45 North America, having a suilline type of dentition, considered by Cope as referable to the family Arctocyonidæ. There are several species; 4. in so lens, the type-species, was as large as a large bear. E. D. Cope, 1873. Achæta (a-ke'tä), n. pl. [NL., neut. pl. of achœtus: see achatous.] An ordinal name for gephyreans without setæ, with a terminal mouth, dorsal anus, and the anterior region of the body retractile. It includes the families Sipunculidæ and Priapulidæ.