CRETACEOUS REPTILES. 403 
who may be of opinion with me, that the statements that have been made 
(Quart. Journ. Geol. Soc. No. 13, p. 2) in proof of the Reptilian and Pterodacty- 
lian character of the fossil remains of Cimoliornis, and especially of the shaft of 
the wing-bone (Tab. XX XIX. fig. 11), are not sufficiently supported by the evi- 
dence adduced from the application of an otherwise valuable instrument in aid 
of paleontological research *. 
* It will be seen that the arguments from the microscopical observation are omitted in the allusion 
to the ‘comparative substance’ of the bones in the paper in the ‘Quarterly Geological Journal,’ 
vol. ii. The author limits himself to the following :— 
“From a comparison of the specimens Nos. 5 and 6 with the figure in the ‘Transactions,’ and 
from my recollection of the original, Iam very much disposed, with due deference to Professor 
Owen, to believe that it may ultimately prove to be the bone of a Pterodactylus instead of a bird.” 
(p- 7.) 
Mr. Bowerbank states that his belief ‘is the more probable, as the bone in question (Tab. XX XIX. 
fig. 11), and the head (pl. 2, fig. 4.) and bones (2d. fig. 6) of the animal now produced, are from the 
same pit at Burham.” As soon as I became aware that Mr. Bowerbank had undertaken the deter- 
mination and description of these fossil bones from the chalk, I obtained permission from the Earl of 
Enniskillen to submit to Mr. Bowerbank those which I had deseribed, and to furnish him with por- 
tions for microscopical examination. He took such portions from the shaft of the wing-bone of the 
longi-pennate bird (fig. 11), and he has given the following results of his comparisons in a supple- 
mentary note to his original paper :—‘ Although the two specimens (fig. 11. Tab. XX XIX. and fig. 7. 
Tab. XXXVIII) differ greatly in size, there is so strong a resemblance between them in the form and 
degree of angularity of the shaft, and in the comparative substance of the bony structure, as to 
render it exceedingly probable that they belong to the same class of animals.” 
Mr. Bowerbank is silent as to the nature or points of resemblance of the ‘comparative substance.’ 
He cannot affirm that the resemblance of form and degree of angularity is less in the humerus of a 
longi-pennate bird to the bone, Tab. XX XIX. fig. 11, than it is in the bone which he compares: he 
admits that “the two specimens differ greatly in size ;” and he also admits that “the flat side of the 
bone described by Prof. Owen is rather more rounded at that portion exhibited by cutting away the 
chalk beneath it, but it gradually becomes less convex as we pass towards the same relative portion 
that is exposed in my specimen,” z.e. fig. 7. Tab. XX XVIII. And Mr. Bowerbank might have added, 
that the obvious points of difference which he here acknowledges to exist between the large bone 
(fig. 11. Pl. XX XIX.) and the small bone (fig. 7. Pl. XXXVI.) are precisely those by which the 
large bone so much more resembles the humerus of the Albatros. 
When such obvious ornithie characters as these, and especially those of the trochlear end of 
the bone, fig. 12, determine their nature, the microscopist must have earned due confidence in his 
judgement as well as his zeal, before the conclusions from those broad anatomical characters can 
be abandoned on the ground of an alleged non-ornithic character of the microscopic radiated 
bone-cell. Now it needs only to compare the range of difference in the length and breadth of the 
radiated cells figured in Quart. Geol. Journ. vol. iv. pl. 1. fig. 1, and the range of difference in the length 
and breadth of the radiated cells in fig. 9 of the same plate, and to know that Mr. Bowerbank affirms 
