128 Reviews — Dollo's Dinosauria of Bernissart. 



descriptions follow of the other elements of the jaw, from which it 

 appears that the coronoid process is formed by the dentary, coronoid, 

 and articular bones. As a whole, the lower jaw perhaps has most 

 correspondence with Satteria. 



The skull in Iguanodon Bernissartensis is 65 centimetres long, 25 

 centimetres wide, and including the mandible, 35 centimetres high. 

 The head is described as having a transversely compressed lacertilian 

 aspect, with the external narines divided, sub-terminal and lateral ; 

 with the orbits lateral, of moderate size, without sclerotic ossifications; 

 the temporal fossa are limited by superior and inferior arcades. The 

 cerebral cavity is completely ossified. Teeth are limited to the 

 maxillary bone. The description treats of the roof of the skull, 

 and its cavities. I cannot give here all the details conveyed in the 

 description and figures; but there are two pre-maxillaries, extending 

 between the nares and forming their anterior and inferior borders. 

 The alveolar margin is edentulous, and no doubt had a horny cover- 

 ing opposed to that of the predentary bone below. It closely 

 resembles the premaxilliary of Jlypsilophodon, except that the bones 

 in Bypsilophodon carry teeth. The maxillary bone is large, uniting 

 anteriorly with the premaxillary, superiorly with the nasal, with a 

 bone termed supra-orbital, as well as with the lachrymal and pre- 

 frontal, while posteriorly it unites with the jugal. On the palate it 

 connects with the external pterygoid, and apparently with the palatine. 

 It carries 25 teeth in use. Its resemblances are with the maxillary of 

 Hatteria and Iguana. It contains towards the lachrymal, a pre- 

 lachrymal vacuity. The nasal bones are long and well developed, 

 forming the roof of the skull between the orbits and nares. The 

 frontal bones have a great transverse expansion, and are large and 

 flat. They margin the orbit above, and on their lateral border are 

 two bones termed supra-orbital. There is no trace of a median 

 suture to the frontals such as characterizes Iguanodon PrestwicJii. 

 The prefrontals each carry a supra-orbital, so that they are hidden 

 laterally. The lachrymal is connected with the prefrontal, maxillary, 

 and jugal. The jugal is attached to a special process of the maxillary, 

 which is given oif some distance in advance of the termination of 

 the alveolar border. This bone unites with the lachrymal, post- 

 frontal, qudrato-jugal, and maxillary. It is stated that there .is a 

 quadrato-jugal, w^hich unites with the quadrate, but in the figure 

 (plate ix. fig. 1) there is no suture to separate the parts of the bone 

 which are lettered respectively jugal and quadrato-jugal. Up to the 

 spring of 1879 I supposed that the quadrato-jugal had no separate 

 existence in Dinosaurs, and so wrote of it ; but I learned better in 

 the autumn of 1879, when, by the courtesy of M. de Pauw, I was 

 enabled to draw the details of the parts of the Bernissart skeletons 

 which were then developed. The post-frontal bone has the usual 

 connections with the parietal, frontal, squamosal, and jngal. It 

 divides the orbit from the lateral temporal fosse, and borders the 

 anterior margin of the supra-temporal fosse. The squamosal bone 

 is connected with the post-frontal, the parietal, supra-occipital, 

 parotic, and quadrate bone. These bones, like the parietals, find 



