. Bulletin of the British Museum (Natural History) Zoology. M 11 . HARRISSON epihyal in halosaurs is thus unusual. In AnguiUa elvers, too, the interoperculum 1^ paddle-shaped (Text-fig. 3). Further, in eels the opercular fold is supported lv by the branchiostegal rays (Regan, £912), while the operculum and sub* â ulum are smalL Except for the large preoperculum, the oalosaur opercular structure thus resembles the condition found in the eels, The details seen in the larva and described above, correspond closely with those given by Marshall (ioj an adult Pop lop sop 11 id "l an
. Bulletin of the British Museum (Natural History) Zoology. M 11 . HARRISSON epihyal in halosaurs is thus unusual. In AnguiUa elvers, too, the interoperculum 1^ paddle-shaped (Text-fig. 3). Further, in eels the opercular fold is supported lv by the branchiostegal rays (Regan, £912), while the operculum and sub* â ulum are smalL Except for the large preoperculum, the oalosaur opercular structure thus resembles the condition found in the eels, The details seen in the larva and described above, correspond closely with those given by Marshall (ioj an adult Pop lop sop 11 id "l an AnguiUa elver showing the bone structure, hmd. op. = operculum, sop. suboperculum, iop. interoperculum, pop. q. = quadrate hyomandibular, preoperculum, I 11 l PREOPERCULUM and Mil. HEAD < \ \ \ The preoperculum may besl be considered in relation to the head canals of the lateral 1: \^ â 1 size in halosaurs (and in these fishes it has secondarily the chid support of the opercular fold) seems related to the enormously : mandibular canal (and not to the infraorbital canal as Marshall, [962, 1 1- no connection between infraorbital and mandibular canals. I\.\\I\ |-6 byGarman(1899)are misleading in this respect; they â 1 jugular connection, present in Dipnoi bul not known in any Actinoptery- The thin walled and greatly expanded canals in the preopercular region are delicate and I in preserved material. In the Larva the infraorbital borl 1 1 the preoperculum, terminating in a backwardly directed bulge 2). Ii -\ adult Aldrovandia examined, the infraorbital canal jusl nda on to the p ilum to end blindly in a series ol finger-like pr< adh( to the | ilai membrane and the wall of the mandibular canal. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Farn, Alexander E. London : Butterworths
Size: 2017px × 1239px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollection, bookpublisherlondonbutterworths
