Ko nga karaehe whakamarumaru kanohi he mohiti haumaru hei aukati i te urunga mai o te huaketo salivary, te puehu, te hae, me etahi atu. He hoahoa pai-kanohi, he waahi nui ake, he pai ake te kakahu o roto.Ko te hoahoa anti-kohu taha-rua.Roopu rapa te whakarite, ko te tawhiti roa rawa atu o te roopu he 33cm.