68 
FOSSIL REPTILIA OF THE 
(the specimen is marked d in the Plate 27 of his Memoir, loc. cit.), and is described 
“ as the body of a vertebra showing a convex articulating surface, as in the Crocodile ” 
(p. 221). Quenstedt’s Fterodactylus suevicus showed similar detached dorsals, in one 
of which it appeared that “ the articular surfaces of the body were convex at the back end, 
and concave at the fore part.”^ Buckland’s specimen serves to dissipate any doubt on the 
point so important in reference to the Crocodilian affinity. It might be assumed that the 
Author viewed the convexity as posterior by the expression “ as in the Crocodile ■” and in 
the last of the dorso-lumbar series, which I regard, with Buckland, as ‘ probably lumbar,’ 
in the sense of not being costigerous, the position of “ its concave articulating surface ’’ is 
demonstrated by those of the articular processes (zygapophyses) at the same end of the 
vertebra, which prove them to be the anterior pair, slightly prominent, looking upward 
and inward. Buckland notes these as “ two anterior spinous processes, an obvious 
typographical error for ‘ oblique ’ or ‘ articular,’ venial in one not professedly an 
anatomist.® 
With regard to the Crocodilian affinity inferred from this structure, it must be remem- 
bered that the procoelian stucture, though it has been observed in Crocodiles from the 
Greensand of New Jersey,® is characteristic of the Tertiary and existing species, rather 
than of the order at large, which had more abundant and diversified (amphicoelian and 
opisthocoelian) representatives in the Secondary ages of Geology. Moreover, the anterior 
concavity and posterior convexity of the vertebral body obtain in most recent, Tertiary, 
and Cretaceous Lacertilia; and finally, the cup- and ball-joints of the centrum appear in 
the dorsal vertebrae of at least one genus of Birds, though with the ball in front.^ 
In the series of nine dorsals, preserved in the subject of PI. XVIII, d, the centrums 
slightly lose length as they recede in position from the neck ; the anterior ones measure 
0 009 mm. =: defines ; the posterior ones measure 0’008 mm. = 4 lines ; the transverse 
diameter of the articular ends is 0'007 mm. = 3 lines. The dorsal vertebra in Buck- 
land’s specimen presents the same dimensions. These dimensions increase as the two or 
three anterior dorsals approach the neck, but the greater enlargement of the last cervical 
is somewhat abrupt. 
For the shape and proportions of the ribs (in the Restoration, PI. XX), I have those 
marked b, c in the original specimen,® and the more numerous and better preserved ones 
' “Die Gelenkfiache der Wirbelkorper war auf der Hinterseite convex, wie beim Crokodil, vorn dagegen 
concav. So scheint es wenigstens.” — Quenstedt, Ueber Fterodactylus suevicus im lithographischen 
Scbiefer Wiirtembergs. 4to, 1855, p. 45. 
2 Buckland, loc. cit., pi. 27. [This vertebra is shown in PI. Ill, fig. 2, of the present Mono- 
graph.] 
^ “Notes on Remains of Fossil Reptiles discovered in the Greensand Formations of New Jersey,” 
‘Quarterly Journal of the Geological Society,’ vol. v, 1849, p. 388. 
^ As in Aptenodytes ; “On the Vertebral Characters of the Order Pterosauria," ‘Phil. Trans.,’ 1849, 
pi. X, fig. 22, p. 163. 
^ Buckland, loc. cit., pi. 27. 
