Keywords: FishKeyDay (cropped).jpg en Skeleton of head of a perch f frontal t turbinal po preorbital io infraorbital ring mx maxillary pmx premaxillary m mandible d dentary bone pt posttympanic s suprascapula o opercle so subopercle pr preopercle iop interopercle br branchiostegal rays Fauna of British India Fishes www archive org 1889 Sir Francis Day pd-old PD-old FishKeyDay jpg Fish skulls Perca |