138 
DR. MANTELL ON A PORTION OF THE LOWER JAW 
dicating a total length of three feet. In the Maidstone Iguanodon there are two 
bones of this kind in a broken state. In none of the skeletons of reptiles, or indeed 
of any other animals, to which I have had access, are there any bones with which 
these fossil osseous remains can be identified. In a very small Lizard in the Hun- 
terian Museum, Mr. Owen pointed out to me a bone attached to the coracoid and 
omoplate, that bore some analogy to the one in question : and I have no doubt that 
a more extended anatomical research will ere long afford a solution to this problem. 
As the position and connexion of this bone with the other sternal elements cannot 
at present be accurately determined, and the term clavicle is manifestly inappropriate, 
and may lead to misconception, I propose to distinguish it by the term Os Cuvieri, 
or the Cuvierian element of the pectoral arch of the Iguanodon, as an humble tribute 
of respect to the memory of the illustrious author of £ Recherches sur les Ossemens 
Fossiles.’ It is satisfactory to find that the correctness of my first appropriation of 
this bone to the Iguanodon, many years before it was found in conjunction with any 
other part of the skeleton, has been confirmed by subsequent discoveries. 
A coracoid , ten inches wide (Plate IX. fig. 11.), was found imbedded in the same 
block of stone with several bones of the Iguanodon. It resembles, in its hatchet-like 
form, the corresponding bone of the Lizards, and, as in that family, it furnishes one- 
half of the glenoid cavity (a) for the reception of the head of the humerus ; but its 
margin ( d ) is entire, and not produced into one or more apophyses, as in the Moni- 
tors, Iguanas, &c. ; and instead of a perforation in the neck of the bone for the pas- 
sage of vessels, there is a deep notch (Plate IX. fig. 2. c ) separating the glenoidal 
cavity from the scapular facet. 
A scapula or omoplate (Plate IX. fig. 10.), eighteen inches long, associated with 
bones and teeth of the Iguanodon, and probably referable to that animal, presents, 
like the coracoid, some important modifications of the usual Lacertian type. This 
bone is of an elongated form, and differs considerably from the omoplate of the Mo- 
nitors and Iguanas. It somewhat resembles the scapula of the Scink, and it throws 
off a long tripartite (fig. 10. h, c, d) apophysis (which is imperfect in the only speci- 
men hitherto discovered) ; this process probably afforded support to a cartilaginous 
arch, as in the recent Lizards. 
But although, from circumstances which it is unnecessary here to detail, I enter- 
tain but little doubt that the coracoid and omoplate above described belong to the 
Iguanodon, it is so hazardous, in palaeontological inquiries, to affirm as certain what 
is merely probable, and so many impediments to accurate inductions have been oc- 
casioned by hasty and positive determinations of a tooth or bone from imperfect ana- 
logies, that I deem it necessary to repeat, that these specimens were not found in 
connexion with other parts of the skeleton of the Iguanodon, but were merely im- 
bedded in the same mass of rock*. 
* A very small symmetrical bone, resembling in form the sternum of a young Iguana, is described (Geology 
of the South-East of England, plate iii. fig. 4.) as the sternum of the Iguanodon ; but the correctness of this 
inference is doubtful. 
