638 



PEOF. H. G. SEELEY OX THE EEPTILE 



fragments of jaw with the teeth, if rightly referred to this genus, 

 present a character similar to that of PriodontognatJius, Scelidosaurus, 

 and AcanthojiJiolis ; but while nearly resembling Scelidosaurus, the 

 tooth-structure is distinctive in the character of the serrations, just 

 as the lower jaw is distinctive in its angularity and vascular foramina. 

 But it is the limb-bones which best define Cratceomus. The scimitar- 

 shaped scapula, with its powerful acromion process, is altogether 

 distinctive, while what remains of the coracoid appears to indicate 

 an equally unusual form. The humeri are remarkably powerful, and 

 indicate an animal strong in its fore limbs, evidently a quadruped, 

 and therefore presumably carnivorous, since the herbivorous forms 

 have the fore limbs feebly developed. The humerus, with a general 

 resemblance to that of Anoplosaurus, is far more robust., and indicates 

 a heavier animal : no bone anterior to the humerus is known. The 

 femur is distinguished from that of the Iguanodonts by wanting the 

 separate external trochanter at the proximal end. It has the arti- 

 cular ends powerfully developed, and, perhaps, most closely resembles 

 in general form that of Gryptosaurus eumerus of the Oxford clay. The 

 tibia is remarkable for the extremely compressed form and forward 

 development of the cnemial crest. The fibula, so far as preserved, 

 is very like the fibula of a bird, and bears a similar relation of size 

 to the tibia. The metatarsal and phalangial bones, if belonging to 

 this genus, rather indicate a flattened foot,terminating in claws which 

 were broad rather than sharp. Taken as a whole, far more difference 

 from Cratceomus is found in described genera in the structure of the 

 internal skeleton than would have been inferred from either the 

 armour or the teeth ; and it is quite possible that the armour, espe- 

 cially in Dinosaurs, may have undergone as little change as the 

 feathers of birds or scales of lizards, so as to be common to several 

 families. 



Mandibles and Teeth probably referable to Crataeomus. 



Three fragments of the anterior extremities of Dinosaurian lower 

 jaws have been found which indicate two species, though the re- 

 mains are so fragmentary that they cannot be defined with the 

 detailed accuracy which is desirable. Both specimens are of about 

 the same size, and belong to a genus which is ' closely related to 

 Priodontognathus. I will describe the more perfect specimen first. 



This species is represented by a dentary bone (PI. XXYII. figs. 9, 

 10), the anterior extremity of which is unfortunately not preserved ; 

 nor is the fragment complete on the hinder or lower border, though 

 it probably gives indications of the whole of the teeth. The alve- 

 olar border is bent in a sigmoid flexure (fig. 9) ; and the bone itself is 

 bent so as to present a flattened lower part at right angles to the upper 

 part of the side behind, but sloping more and more outward in front. 

 The lateral contour of the alveolar border is convex, rising higher in 

 the middle and descending to near the level of the base ; it has 

 a width of about 6 centimetres. As usual with Dinosaurs, it is 

 higher on the external than on the internal margin. The teeth 

 were placed in sockets defined and separated by narrow bony inter- 



