"——— = 
21 
January 28, 1851. 
R. H. Solly, Esq., F.R.S., in the Chair. 
The following papers were read :— 
1. ON A NEW SPECIES OF PrERODACTYLE (PTERODACTYLUS COM- 
PRESSIROSTRIS, OWEN) FROM THE CHALK; WITH SOME Re- 
MARKS ON THE NOMENCLATURE OF THE PREVIOUSLY DE- 
SCRIBED species. By Pror. Owen, F.R.S. 
(Reptilia, Pl. V.) 
The honour of having first made known the existence of remains 
of the Pterodactyle in the Chalk deposits belongs to James Scott 
Bowerbank, Esq., F.R.S. This indefatigable collector had the good 
fortune to receive in 1845, from the Kentish Chalk, the characteristic 
jaws and teeth, with part of the scapular arch and a few other bones, 
of a well-marked species of Pterodactyle, and the discovery was briefly 
recorded in the ‘ Quarterly Journal of the Geological Society of Lon- 
don,’ and in the ‘ Proceedings’ of the Society for May 14, 1845, with 
an illustrative plate (pl. 1). 
Mr. Bowerbank concludes his notice by referring to a large fossil 
wing-bone from the chalk, previously described and figured by me in 
the ‘ Geological Transactions,’ and remarks that, “if it should prove 
to belong to a Pterodactyle, the probable expansion of the wings 
would reach to at least eight or nine feet. Under these circum- 
stances,” he says, “I propose that the species described above shall 
be designated Pterodactylus giganteus.” (loc. cit. p.8.) Subsequent 
discoveries and observations have inclined the balance of probability in 
favour of the Pterodactylian nature of the fossils to which Mr. Bower- 
bank refers, but have shown them to belong to distinct species. 
These fossils are not, indeed, amongst the characteristic parts of 
the flying reptile: one of them is the shaft of a long bone exhibiting 
those peculiarities of structure which are common to birds and ptero- 
dactyles ; the other shows an articular extremity, which, im our pre- 
sent ignorance of those of the different bones of the Pterodactyle, has 
its nearest analogue in the distal trochlea of the bird’s tibia. These 
two specimens, which are figured in the sixth volume of the Second 
Series of the ‘Transactions of the Geological Society,’ 1840, pl. 39. 
figs. 1 & 2, were transmitted to me by the Earl of Enniskillen and 
Dr. Buckland, as being “the bones of a bird” (p. 411), and my com- 
parisons of them were limited to that class. 
The idea of their possibly belonging to a Pterodactyle did occur to 
me, but it was dispelled by the following considerations. The act of 
flight—the most energetic mode of locomotion—demands a special 
modification of the Vertebrate organization, in that subkingdom, for 
its exertion. But in the class Aves, in which every system is more or 
less adapted and co-adjusted for this end, the laws of gravitation seem 
to forbid the successful exercise of the volant powers in species beyond 
a certain bulk ; and when this exceeds that of the Condor or Albatros, 
