18 
we take into consideration the comparative length of each bone with 
regard to its total extension, as exhibited in the table of the dimen- 
sions of P. longirostris. In the case of the great specimens of radius 
we may arrive at their length in many cases, although the bone may 
be imperfect at even both terminations. Thus the diameter of the 
smallest portion of the bone formerly in the possession of the Earl of 
Enniskillen and figured by Prof. Owen, is *81 inch at the smallest 
portion of the shaft: this bone therefore, on the scale of 133 diame- 
ters to its length, should be 10°93 inches in length. The measure- 
ment of the smallest portion of the bone belonging to Mrs. Smith 
(Geol. Journ. vol. iv. pl. 2. fig. 1a) is*77 mch: we may therefore, by 
the same rule, conclude that its length was 10°39 ches when per- 
fect. The length of the imperfect ulna beside it is 9°25 inches in the 
specimen. The diameter of the smallest portion of the bone (Geol. 
Journ. vol. ii. pl. 1. fig. 6) is *45 inch, which, in the proportion of 13} 
diameters to its length, will give 6°07 inches for its length. The 
width of the corresponding bone in the possession of Mr. Charles of 
Maidstone is 1°25 inch at the smallest diameter: by the same rule, 
therefore, the approximate length should be 16°87. The remains of 
the bone alongside of it is, although imperfect at both ends, actually 
12°25 inches in length. 
Upon these grounds therefore, in every case derived as much as 
possible from direct measurements from the skeletons of the respective 
species, I have given the following table of the dimensions of a series 
of species of Pterodactyls, the most interesting either from the state 
of perfection in which their remains have been found, or from the 
gigantic proportions which they present; and thus have endeavoured 
to realize to the mind an idea, as nearly as possible correct, of the di- 
mensions of the animals when alive. 
Table of the relative proportions of known species of Pterodactylus, 
with the length of each of the wing-bones and half of the width of 
the body. 
3 co 3 s |% 1 ot 
ia aa Mae Me a BP re uth 
BE ils¢ia) 2121221 2 |Pe/3gs 
Bles(e | 2/8] e151] & je*|gee 
Bike ooleSol 2ch.4.| Sioa lees 
in in. fin. in. in. in. in. in, ft. in. 
P. brevirostris ...| 0°48 | 0°75 |0°06| 0°52| 0°82] 0°76] 0°48} 0°35 |0°19| 0 9 
P. longirostris ...) 1°25 | 1-90 0°13 | 1°34] 1:90] 1°75} 1:25] 1:17 |0°47) 1 10 
P. crassirostris...| 2°08 | 4°42 0°34] 1°32] 2°83] 2°53] 2°08] 2°32|1°10| 3 2 
P. Bucklandi.....| 3°25 | 4°25 0°40} 3°75 | 3°91] 4°83] 3°25] 3:00/1°06| 4 7 
P. grandis ........ 3°75 | 5°70 0°39] 4°02] 5°70) 5°50} 2°75) 3°51 (1-42/5 5 
P. giganteus...... 4:43 | 6°74 0°46 | 4°75] 6°74) 6-21] 4:43) 414/168) 6 7 
P. (Mrs.Smith’s)} 6°76 |10°39 0°70 | 7°26 |10°39| 9°49] 6°76] 6°33|2°59 |10 2 
P. Cuvieri ........{10°99 |16°87 |1-14 |11°79 |16°87 |15°56 |10-99 |10°29 |4°22 |16 6 
In the above table I have presumed that the largest bones should 
be associated with the snout described as the type of P. Cuvieri, but 
the truth of this assignment of the bones belonging to Mr. Charles 
