76 
FOSSIL REPTILIA OF THE 
of two equal-sized, closely and extensively united bones, with one or two slender styliform 
ossicles attached lengthwise, having the base a little below the distal ends of the radius 
and ulna. The latter bone shows no pits for the attachment of quill-feathers, as in the 
hot-blooded volant Ovipara. A carpus with one large and one small bone in a proximal 
row, and with a second large and at least one smaller bone in a distal row, is another 
character by which the Pterosauria manifest their closer affinity to Reptiles than to 
Birds. The remains of the gigantic species from the Cambridge Greensands have yielded 
the characters of the two larger carpal ossicles.^ 
Variation, as usual, begins to assert its sway as the segments of the limb recede from 
the trunk. This is mainly shown in the relative length of the metacarpus. In Bampho- 
rhynclms Gemmingi it is to the antibrachium as 2 to 7, and to the first phalanx of the 
wing-finger as I to 5, or rather less. In Dhnorphodon the metacarpus is to the 
antibrachium rather more than 2 to 6, and is little less than one half the length of the 
first phalanx of the wing-finger. In Pterodactylus longirostris the metacarpus is 
two thirds the length of the first phalanx. In Pterodactylus longicollum the metacarpus 
is almost four fifths the length of the first phalanx of the wing-finger. In Pt. suevicus 
the metacarpus is one eighth longer than the antibrachium. 
There are diversities also in the relative length of the phalanges of the wing-finger. 
In DimorpJiodon they increase in length from the first to the third. In Bamphorynchus 
Gemmingi the first and second phalanges are of equal length, and the third is shorter. In 
Pterodactylus longirostris, Pt. scolopaciceps, Pt. Kochii, they decrease in length from the 
first to the third, and in a greater degree in Pt. suevicus. 
The most marked variety, however, if the structure has been rightly determined or 
be not due to some accidental mutilation of the individual, is that on which Von Meyer ^ 
has founded his genus Ornithopterus, viz. a reduction in the number of phalanges of the 
wing-finger from four to two, and the articulation of the proximal one to two large 
metacarpals. The last pointed phalanx of the wing-fiuger in Bamphorhynclms is rather 
longer than the penultimate one ; in Ornithopterus Lavateri it is only one third the 
length of the penultimate phalanx. 
The evidences of pelvic structure in other Pterosauria, already referred to, leaves no 
doubt as to that in Dimprphodon, as restored at s, 62, 63, 64, in PI. XX. The 
expansion of the ischial and pubic elements and the direction of the latter are strong 
evidences of Reptilian affinity, and decisive differences in the comparison with Birds. 
Given the greatest number of vertebrae grasped by the ilia, it falls short of the least 
number presented in the class of Birds, as by certain Natatores, which concomitantly 
manifest a vacillating or waddling gait. Nothing in the structure, proportions, and con- 
nections of the pelvic arch squares with the notion of bipedal progression or erect 
sustentation of the body and wings of the Pterosaur. The share taken by the hind lirnbs 
1 ‘Monograph,’ Suppl. No. Ill (1861), p. 17, PI. II, fig. 6; PI. IV, figs. 5 — 9. 
2 Op. cit., p, 25, pi. vi, fig. 5. 
