By a simple modification, the open pit becomes a solid ectodermal ingrowth, just as in Teleostean fishes the hollow medullary tube, or the auditory pit of other vertebrate embryos, is formed at first as a solid cord of cells, which acquires a cavity secondarily.
To this category will belong the oviducts in Teleostean fishes and probably the gonad ducts in several groups of invertebrates.
COD, the name given to the typical fish of the family Gadidae, of the Teleostean suborder Anacanthini, the position of which has much varied in our classifications.
This type of caudal fin must be regarded as secondary, the Gadidae being, no doubt, derived from fishes in which the homocercal fin of the typical Teleostean had been lost.
He has shown that, as in the Crossopterygian and Chondrostean ganoid fishes, there co., are two clavicular elements on each side; the lower corresponds to the clavicle of reptiles and higher vertebrates, whilst the upper corresponds to the clavicle of teleostean fishes, and has been named by him "cleithrum."