[Illustration: Fig. 7. Vertebrae of _Eusthenopteron_ (×1) and _Ichthyostega_ (×2/3, after Jarvik, 1952), _Trimerorhachis_ (×1-1/2, after Case), and _Amphibamus_ (×10, after Watson, 1940) in lateral and end views; the two lower right-hand figures are from Watson (1940, as _Miobatrachus_); the lower left is from a cast of the "_Miobatrachus_" specimen in Chicago Natural History Museum, No. 2000, in the presacral region (original, ×10).] Fig. 7, lower right, is Watson's (1940) illustration of the anterior trunk vertebrae of _Amphibamus_ (_Miobatrachus_), in which the intercentrum is shown as a single median piece. Fig. 7, lower left, shows two of the more posterior trunk vertebrae seen as impressions in a cast of the type of "_Miobatrachus romeri_;" evidently the inter-centra were paired at about the level of the 16th vertebra, and relatively large. Gregory's (1950) figure of the type specimen of "_Mazonerpeton_" (also equivalent to _Amphibamus_) shows the anterior trunk vertebrae in relation to the ribs essentially as they appear to me in the cast of _Miobatrachus_, and rather differently from Watson's figure of the latter. Gregory is probably right in considering the specimens to represent various degrees of immaturity. So far as present information goes, then, the vertebrae of salamanders and frogs show no _clear_ evidence of derivation from those of any particular group among the early Amphibia, but their features are not inconsistent with a simplification of the pattern of Temnospondyli. [Illustration: Fig. 8. Pectoral girdles of _Protobatrachus_ (after Piveteau, 1937), _Notobatrachus_ (after Stipanicic and Reig, 1956), Ascaphus (after Ritland, 1955 a) and _Rana_ (original); all ×2. For explanation of abbreviations see Fig. 3.] PECTORAL GIRDLE Hecht and Ruibal (Copeia, 1928:242) make a strong point of the nature of the pectoral girdle in _Notobatrachus_, as described recently by Stipanicic and Reig (1955, 1956) from the Jurassic of Patagonia, and quite rightly recommend that the significance of the arciferal and firmisternal types of girdle be restudied. That of _Notobatrachus_ is said to be firmisternal; in view of the arciferal condition in the supposedly primitive _Leiopelma_, _Ascaphus_, _Bombinator_, etc., this comes as a surprise. Is the firmisternal girdle, as seen in _Rana_, _Bufo_, and others, actually the ancestral type, and has the arciferal been derived from something like this?