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FOSSIL REPTILIA OF THE 



produced ; the body of the vertebra is narrower, but deeper, than in the more 

 advanced vertebra (fig. 1). The posterior zygapophysis is surmounted by a 

 tubercle. 



Caudal Vertebra (Tab. II, figs. 13—16). 



The caudal vertebra, from the anterior half of the tail (figs. 13 and 14), presents 

 a size corresponding with the proportions of the Pterodactyle given by the above- 

 described neck-vertebrse ; the neural arch and zygapophyses continue to be dis- 

 tinctly developed at this region of the tail. There is a foramen ( G ), leading into 

 the substance of the neural arch, on each side of the back part of that arch, and 

 near the corresponding outlet of the neural canal. In the more distal vertebra 

 (figs. 15 and 16) the neural arch has sunk, and seems almost blended indistin- 

 guishably with the centrum, which is much longer than in the vertebrae nearer 

 the trunk. The zygapophyses cease to be developed ; but the articular, shallow 

 cup and ball at the ends of the vertebra show that the tail retained its 

 mobility, and was not stiffened or anchylosed as at the corresponding part in 

 Hamphorhynchus. 



The Sternum (Tab. II, figs. 7—12). 



According to the very able and instructive summary, by M. V. Meyer, of the 

 osteology of the best-preserved examples of the skeletons of Pterodactyles, those, 

 viz., from the lithographic slates of the Jurassic (Mid-oolitic) series of rocks, the 

 sternum is a compound bone, consisting chiefly of a symmetrical, keelless, broad 

 plate,* having an anterior process answering to the episternal process in the 

 crocodile,t and with distinct side parts, having articulations for a few bony, 

 sternal ribs. J As to its resemblance, otherwise, to the sternum of mammals, birds 

 or reptiles, in regard to the articular surfaces for the scapular arch, nothing has 

 been, hitherto, determined. 



* " Das Brustbein ist ein schwach gewolbtes knochernes Schild, das breiter als lang, und daher eher 

 dem Brustbein der nur kiimmerlich mit Fliigeln versebenen Strauss-artigen Tbiere beider Erdhalften, als 

 dem in den Flug-begabten Vogeln zu vergleicben ist. Es zeigt keinen Kiel oder Gratb, und Man konnte 

 daher glauben, das die Stelle zura Ansatz eines kraftigen Flugmuskels feblt, die Pterodactyln keine gute 

 Flieger gewesen waren." ('Reptilien aus dem Lithograpbiscben Schiefer,' fob, 1859, p. 17.) 



f " Am Brustbein der Pterodactyln wird ein vorderer Forsatz wahrgenommen, der den Kiel ersetzt unt 

 den Brustmuskeln als Anbeftungsstelle gedient haben wird. Dieser Theii erinnert au den Forsatz am 

 Brustbein des Crocodils." (Ibid., p. 18.) 



% " Bei Ramphorhynchus Gemmingi fand ich ausser den gewohnlichen Brustbein nach eine Platte mit 

 Brustrippe welche die Verbindung mit den Kiickenrippen unterbalten haben werden und wie in den 

 Vogeln knochern waren." (Ibid., p. 18, tab. x, fig. 1.) 



