ANNIVERSARY ADDRESS OF THE PRESIDEN. ‘51 
from Hypsilophodon; and the fixity of the quadrate, which is rendered 
incapable of movement by the abutment of the quadrato-jugal and the 
pterygoid against it, and by the closeness with which the squamosal 
embraces its upper end and also descends upon its surfaces, a dis- 
position of this latter bone which has some resemblance to that 
obtaining in Amphibians and Ganoids. 
In a short account of the vertebral column, M. Dollo states that 
it contains 85 vertebre ; of these 10 are cervical, 18 dorso-lumbar, 
6 sacral, and 51 caudal. The forms of the articular surfaces of the 
centra in these several regions agree with those in J. Prestwich 
figured by myself in our Journal; and thus M. Dollo’s labours 
afford an additional proof of the critical acumen of those early 
paleontologists Drs. Melville and Mantell. M. Dollo finds that the 
neurapophyses of the atlas were synchondrously united superiorly, 
and he has not discovered any trace of preatlas or capping-piece, 
which some have regarded as the modified neural spinous process. 
Thus in Jguanodon the atlas appears fashioned on the Lacertilian 
pattern, which is noteworthy, since the other presacral vertebre 
have Crocodilian rather than Lacertilian features. In the sacrum 
M. Dollo finds 6 vertebree—one more, therefore, than in the type 
sacrum of J. Mantelli in the British Museum; but I am in 
doubt whether Dollo does not include in the sacrum the last lumbar 
vertebra, which in old individuals is usually united by synostosis to 
the first sacral, and is functionally inseparable from it. Should this 
be the case, Dollo’s views in this matter are in accord with those of 
“Melville and Mantell, who for this and other interpretations were 
once so harshly censured. An expression M. Dollo uses with respect 
to diapophyses, ‘‘ upper transverse processes,” leaves me in doubt, 
also, whether he considers these absent from the sacrum. A very 
instructive fragment of a sacrum of an immature J. Mantelld in my 
own collection, shows slender ‘“‘ upper transverse processes,” diapo- 
physes, outgrowth from the neurapophyses in the level of the crown 
of the neural arch: and massive ‘“‘ lower transverse processes,” para- 
pophyses, of which the original distinctness from the vertebral centrum 
is indicated by the still obvious suture which marks their union. | 
I have already noticed some interesting points of resemblance in 
the cranial structure of Jguanodon to similar ones in Amphibia 
and certain Ganoids, at the lower end of the vertebrate scale, . and 
in the higher vertebrates, man included. It may be here remarked 
that similar resemblances are observable in respect of the vertebral 
column. Thus, in Jguanodon, the cervical vertebre are. opisthocee- 
lous ; they are soin Salamander, in Pipa, and in Lepidosteus ; so also 
are they in certain cervicals in some higher Mammalia, a familiar 
instance of which is the horse. In Jguanodon, in the sacrum, the 
neurapophyses are intervertebrally situated ; this is also their rela- 
tion to the centra throughout the vertebr al column in the Ganoid 
Amia. 
More attractive probably to the larger number of ee than 
his ‘ Quatriéme Note” just cited, will he found Dollo’s. “‘ Troisiéme 
Note,” in which he describes the pelvic girdle and hind limbs, and 
gives an excellent representation of one entire skeleton, as mounted 
