(1) Naef (1929) considered the rib-bearer a derivative of the basiventral, which, by spreading laterally and dorsally to meet the neural arch, enclosed the vertebral artery. He then supposed that by reduction of the rib-bearer in other tetrapods (frogs and amniotes) the vertebrarterial foramen and costal foramen were brought together in a single foramen transversarium. The implication is that the Urodele condition is primitive, but it cannot now be supposed that Urodela are ancestral to any other group, and the rib-bearer is most probably a specialization limited to salamanders. This does not, of course, invalidate the first part of his interpretation. (2) Remane (1938), noting that rib insertions of early Amphibia are essentially as in Amniota, argued that the rib-bearer is not from the basiventral but is a neomorph which originates directly from the neural arch and grows ventrally. This he inferred mainly from Gamble's (1922) observation on _Necturus_, but his assumption that _Necturus_ is more primitive than other salamanders (such as the Salamandridae), where the pattern differs from this, is not necessarily correct. Rather, the perennibranchs are distinguished mainly by their neotenous features, and their development is likely to show simplifications which are not necessarily primitive. The suggestion of a "neomorph" ought not to be made except as a last resort, for it is simply an acknowledgment that the author does not recognize homology with any structure already known; sometimes further information will make such recognition possible. (3) Gray (1930), using _Molge taeniatus_, concluded that the normal capitulum of the rib was lost, but that the tuberculum bifurcated to make the two heads seen in Urodela, thus accounting for the failure of the costal foramen to coincide with that of the vertebral artery. This answer, too, seems to entail an unprovable assumption which should not be made without explicit evidence. (4) Finally, Emelianov (1936) regarded the rib-bearer as a rudimentary _ventral_ rib, on account of its relationship to the vertebral artery, and considered the actual rib to be a neomorph in the _dorsal_ position characteristic of tetrapod ribs in general. This argument would fit the ontogenetic picture satisfactorily, provided that (_a_) there were some evidence of ventral, rather than dorsal, ribs in early Amphibia, and (_b_) we accept the invention of another neomorph in modern Amphibia as an unavoidable necessity. Emelianov's conclusion (p. 258) should be quoted here (translation): "The ribs of Urodela are shown to be upper ribs, yet we find besides these in Urodela rudimentary lower ribs fused with the vertebral column. The ribs of Apoda are lower ribs. In Anura ribs fail to develop fully, but as rare exceptions rudiments of upper ribs appear."