Alimentary canal rarely coiled, occasionally with glands which are simple caeca and sometimes serve as air reservoirs; jaws often present and an eversible pharynx.
Parapod.ia hardly projecting; palps of prosomium forming branched gills; no pharynx or eversible buccal region; no septa in thorax, septa in abdomen regularly disposed.
The buccal region is unarmed and not eversible.
The distal extremity of this apparatus is sometimes eversible as a penis.
There is no reason in the actual significance of the word why the term " proboscis " should be applied to an alternately introversible and eversible tube connected with an animal's body, and yet such is a very customary use of the term.