1847.] BOWERBANK ON THE PTERODACTYLUS GIGANTEUS. 5 
other birds which I examined for the purposes of comparison ; and 
that the latter were in every respect in accordance with those of the 
Albatros, while the bone-cells of the former exhibited the same small 
diameter and great elongation as well as the other peculiarities which 
characterized the bone-cells from the jaw of the Pterodactyl and from 
the large bone from the collection of the Karl of Enniskillen. 
In the same paper by Prof. Owen on the supposed Ornitholites from 
the chalk, there is a second bone which is deseribed as the “ distal 
extremity of the tibia of probably the same bird,” and is represented 
in the Plate by fig. 2. I did not receive any fragments of this 
bone for examination ; but another specimen of the like description of 
bone, from I believe the same chalk-pit near Maidstone, has been 
obtamed by Mr. Toulmin Smith, who has kindly allowed me to 
examine and figure it in illustration of this paper. It has been seen 
and compared with the figured specimen by Prof. Owen, and I am 
informed that he considers it as the same description of bone as the 
one represented by fig. 2 m his paper in the Transactions of the 
Geological Society. 
On examining some small fragments of this bone taken from the 
broken end of the shaft at the pomt the farthest removed from the 
head of the bone, with a power of 500 linear, I found the bone-cells, 
which are represented at fig. 5. Pl. II., to correspond precisely in all 
their characters with those from the jaw of the Pterodactyl. 'The 
average measurement of five of them, represented at fig. 5. Pl. I1., was 
—length =1, inch, greatest diameter =,,, mch. I have therefore no 
hesitation im considering this specimen, as well as the long bone from 
the collection of the Karl of Enniskillen, as truly reptilian, and not as 
the remains of a bird. 
In my former paper on the Pterodactylus giganteus, I stated that 
from a comparison with the figures of Pterodactylus by Goldfuss, I 
believed that the bone represented by fig. 6 in the illustrations to that 
paper was an ulna, but unfortunately both that bone and the one in 
the possession of the Harl of Enniskillen were so imperfect towards 
their extremities that it was exceedingly difficult to decide that point 
with any degree of certainty. Fortunately the two fine specimens 
from the rich collection of Mrs. Smith of Tunbridge Wells, represented 
by fig. 1. Pl. II., ina great measure justify this conclusion, and in 
the bone a, which is apparently the corresponding bone to the one 
represented by fig. 1 m Prof. Owen’s paper, the head is very nearly 
in a perfect state of preservation. It presents a simple cupped ex- 
tremity, as represented by fig. 2, while the extremity of the second 
bone 6 has suffered so much as to render its form quite indistinct. 
The animal to which they belonged must have been of enormous 
dimensions, for there is a further portion of the shaft of the bone 4 
imbedded on the mass of chalk, which makes the whole length of the 
specimen 94 inches, and the extremity of this part of the shaft does 
not exhibit any indication of its being near to the opposite end of 
the bone. There are also two other similar bones imbedded side by 
side in the collection of Mr. Charles of Maidstone, of still greater 
dimensions than those from the cabinet of Mrs. Smith. The head of 
