Noungill cover; operculum

Noungill slit · pharyngeal slit

Noungill slit

Nounsea pen (any coelenterate of the family Pennatulidae or related families); sea feather

Nounchin; jaw · gills; branchia

Nounbranchial arch; gill arch

Noungill lamella; branchial lamella; gill filament

Noungill plate; branchial plate; gill lamella; branchial lamella

Noungill sac; branchial sac; branchial pouch; inner branchial groove; pharyngeal pouch

Nounctenidium; comb gill

Nounexternal gill

Nounlamellibranches (i.e. bivalves)

Nounenteropneusts (hemichordates of class Enteropneusta)

Nounpterobranchs (hemichordates of class Pterobranchia)

Nounelasmobranchs

Nounprosobranchs

Nounopisthobranchs

Nounnudibranchs

NounHeterobranchia; clade of snails and slugs

Nounjawbone; mandible · branchial arches (in fish); gill arches

Nounbranchial respiration

Nounbeing square-jawed

Expressions (phrases, clauses, etc.), Godan verb with 'ru' endingto be square-jawed