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to be developed from the back part of that of the eighth dorsal, and the metapophysis, from 

 the front part of that of the ninth : this ascends upon the anterior zygapophysis of the 

 twelfth dorsal. Both accessory processes are of considerable length in the lumbar region, 

 except in the last two vertebrae. The lumbar spines progressively increase in length to the 

 last, and are strongly inclined forwards towards that of the eleventh dorsal, which is vertical ; 

 the antecedent dorsal spines inclining backwards to the same vertebra, which is the centre of 

 the movements of the trunk. The spines of the sacral vertebrae converge to the middle one, 

 which is long and strong. The neural canal becomes exposed on the ninth vertebra of the tail. 

 There are hsemal arches and hypapophyses beneath most of the caudal vertebrae. Seven an- 

 terior pairs of ribs articulate directly with the sternum, which consists of six bones. The lower 

 costa of the scapula forms an acute angle with the base, and the infraspinal fossa is much 

 broader than the supraspinal one, the spine of the scapula curving towards the upper angle. 

 The acromion is moderately long and slender, the tuberosity answering to the lower division 

 in the Caviadte. The clavicles are strong, and curved backwards at their outer half. The 

 humerus is perforated at the inner condyle, but not between the condyles. The bones of the 

 fore-arm have a long and wide interosseous space, and allow of free pronation and supination. 

 The hand is pentadactyle, and the whole anterior extremity much shorter than the posterior 

 one. The iliac bones extend upwards considerably above their junction with the anterior 

 sacral vertebrae, and curve outwards. The tuberosities of the ischia are unusually developed. 

 The thyroid, or obturator vacuities are very extensive, the size of the pelvis according with 

 that of the hinder extremities. The great trochanter is of unusual length, is expanded and 

 slightly bent at its extremity. The fossa upon the neck of the femur is unusually deep ; 

 there is no third trochanter. The medullary artery enters on the inner side of the base of 

 the small trochanter. The slender fibula coalesces with the lower third of the tibia, but both 

 its extremities are free, and the lower one is detached, as in the Chevrotain, from the rest of 

 the bone. The calcaneum, astragalus, and cuboid are all remarkable for their length : the 

 scaphoid sends a long and thick process downwards and forwards to beneath the middle 

 cuneiform and the base of the metatarsus of the second toe. There is an oblong ossicle 

 attached to the inner side of the base of the same metatarsal ; but whether it be the ento- 

 cuneiform, or a rudiment of the metatarsal of the hallux, is not determinable in this skeleton, 

 as the tarsus appears to be incomplete at its inner side. In the skull of this remarkable 

 species of Rodent, the occipital region, owing to the enormous development of the acoustic 

 bullse, appears as a broad shallow depression between them at the back part of the skull. 

 The paroccipitals are small, slender, subelongate, and project downwards, distinct from the 

 bullse. The broader mastoid processes are applied to the outer side of the petrosal portion 

 of the bullae : the swollen bases of the mastoids form a tract upon the upper surface of the 

 cranium larger than the interparietal bone, on each side of which they are situated. The 

 slender posterior clamping processes of the squamosals impress the outer sides of the bullse 

 which they support, above the ' meatus externus ' : this canal is directed upwards and a little 

 outwards. The parietals are pushed by the squamosals entirely to the upper region of the 

 cranium : the sagittal suture remains, as well as the frontal one. The temporal muscles 

 seem to have been unusually small in this Rodent : their fosses impress only the small squa- 

 mosals. The coronoid process of the lower jaw is obsolete. The movements of the jaws 



