Paired
81anterior cardinal vein — paired veins draining blood from the head into the common cardinal veins …
82atrial frill — paired ventral structures on the posterior trunk on each side of the tail in Bothriolepis canadensis (Placodermi). Suggested to be ventral fins, claspers or an external shell gland …
83clavicle — paired dermal bone ventral to the cleithrum in Acipenseridae and Amiidae. Lost or fused with the cleithrum in Teleostei. Clavicle was sometimes misapplied for cleithrum …
84posterior cardinal vein — paired veins from the posterior part of the trunk originating in the renal and segmental (intercostal and interspinous) veins and lying on each side of the dorsal aorta and between the kidneys …
85renal vein — paired veins draining the kidneys into the posterior cardinal veins, q.v …
86urodermal — paired, thin dermal bones at the rear of the caudal fin skeleton, derived from scales …
87Wilder’s organ — paired serrated appendages in the gill chamber attached to the isthmus by connective tissue and some sternohyoideus muscle fibres in Amia (Amiidae). It is supported by bone and equipped with tooth like structures. Function unknown …
88cerebral eyes — Paired eyespots embedded in or near the substance of the brain area …
89bigeminal — Paired; double; twin …
90lateral cups — Paired element of nauplius eye of nonmalacostracan crustaceans [McLaughlin, 1980] …