▁glob ular ▁structure , ▁ar ising ▁from ▁the ▁base ▁of ▁the ▁lab ium . ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ ▁ ▁It ▁ass ists ▁sw allow ing . ▁It ▁performs ▁the ▁role ▁of ▁the ▁tongue ▁found ▁in ▁large ▁verte br ates . ▁ ▁My ri ap ods ▁ ▁My ri ap ods ▁compr ise ▁four ▁classes ▁of ▁ar th rop od , ▁each ▁with ▁a ▁similar ▁morph ology : ▁Class ▁Ch il op oda ▁( cent ip edes ); ▁class ▁D ip lop oda ▁( mill ip edes ); ▁class ▁P au rop oda ; ▁and ▁class ▁Sym phy la . ▁My ri ap od ▁mouth parts ▁are ▁similar ▁to ▁those ▁of ▁che wing ▁insect s , ▁although ▁there ▁is ▁some ▁variation ▁between ▁the ▁my ri ap od ▁classes . ▁ ▁A ▁lab rum ▁is ▁present ▁but ▁sometimes ▁is ▁not ▁obvious ▁and ▁forms ▁an ▁upper ▁lip , ▁often ▁in ▁association ▁with ▁an ▁ep ist ome . ▁ ▁The ▁lab ium ▁is ▁formed ▁by ▁first ▁max illa e ▁in ▁dip lop oda ▁forming ▁the ▁g n ath och il arium . ▁ ▁The ▁pre oral ▁cav ity ▁so - formed ▁contains ▁pa ired ▁mand ibles ▁and ▁any ▁max illa e ▁which ▁are ▁present . ▁ ▁For cip ules ▁Cent ip edes , ▁in ▁addition ▁to ▁their ▁mouth parts , ▁possess ▁a ▁pair ▁of ▁" po ison ▁cla ws ", ▁or ▁for cip ules . ▁ ▁These , ▁like ▁the ▁max ill ip eds ▁of ▁cr ust ace ans , ▁are ▁modified ▁legs ▁and ▁not ▁true ▁mouth parts . ▁