324 



NA TURE 



[August I, 18S9 



has the movement been along certain Hnes, that the bands 

 of greywacke and shale have been intensely crumpled 

 and puckered, and have actually been converted locally 

 into fine micaceous schists. 



Hence it seems tolerably certain that though in the 

 west of Ireland the chief plications, fractures, and 

 metamorphism were completed before Upper Silurian 

 time, and though a vast interval must have elapsed during 

 which the progress of denudation laid bare the younger 

 schists, and thereby provided materials for the Upper 

 Silurian conglomerates, the terrestrial disturbances never- 

 theless continued during the deposition of these con- 

 glomerates, and were renewed with increased vigour 

 after. vards. 



If we compare the geological structure of the Silurian 

 tracts of England, Wales, and the south of Scotland, and 

 the east of Ireland, with that of the areas of the younger 

 crystalline schists, many points of resemblance will be 

 seen to occur between them. Towards the north and 

 north-west we find that the Archaean, Cambrian, and 

 oldest Silurian rocks, now exposed there by the progess 

 of denudation, have been subjected to the intensest 

 mechanical deformation, and have assumed the most 

 completely schistose structures. Coming southward, we 

 trace the younger crystalline schists of the Central High- 

 lands and of Donegal thrown into innumerable north-east 

 and south-west folds, and becoming less and less meta- 

 morphosed as they are followed towards the lower 

 grounds. Still further south the Lower and Upper 

 Silurian rocks, plicated, crumpled, and dislocated, repeat 

 the familiar structure of the Southern Highlands, but with 

 only partial and feeble metamorphism. I am disposed to 

 look upon the whole of these structures as the result of 

 one great succession of terrestrial movements which 

 began and reached their maximum of intensity during 

 some part of Lower Silurian time, but which continued to 

 repeat themselves at intervals with greater or less vigour 

 through a long series of geological ages, down to the 

 early part of the Old Red Sandstone period. 



As the consequence of this prolonged disturbance, the 

 Archaean and older Palaeozoic rocks have been thrown into 

 those north-east and south-west folds, which have in large 

 part determined the trend of the land in the north-west of 

 Europe. The shaping of our mountains into their present 

 forms has been brought about by ages of subsequent 

 sculpture, in which the agencies employed by Nature have 

 operated mainly on the surface, but the carving of their 

 features has been guided by the internal structures 

 developed by those subterranean movements which we 

 have been considering. 



THE ENTIRE SKELETON OF AN ENGLISH 

 DINOSA UR. 



C OME years ago an article appeared in the columns of 

 •^ this journal (vol. xxviii. p. 439), in which a notice 

 was given of the marvellously preserved skeletons of 

 Iguanodon from the Wealden deposits of Bernissart, in 

 Belgium, some of which are now exhibited in the Brus- 

 sels Museum of Natural History. In that article the 

 author very properly insisted upon the extreme import- 

 ance of those specimens from an anatomical point of 

 view, as exhibiting the whole of the bones of the skeleton 

 in their natural juxtaposition. He was, however, probably 

 then unaware (as the undermentioned specimen was not 

 at that time exhibited to the public) that the British 

 Museum possessed the skeleton of an English Dinosaur, 

 which, although of smaller size than the Bernissart 

 Iguanodons, belongs to the same sub-ordinal group, and 

 exhibits equally clearly the mutual relations of the com- 

 ponent bones. The English skeleton is, indeed, in some 

 respects much more satisfactory than the Belgian speci- 

 mens, inasmuch as its bones have not been flattened and 



crushed in the manner which so sadly disfigures those of 

 the latter. Further, the English Dinosaur has an addi- 

 tional interest in that it is one of quite the earlier mem- 

 bers of the group, its geological horizon being the Lower 

 Lias of Dorsetshire. 



This specimen, as being the only known example of 

 the almost entire skeleton of a Dinosaur from English 

 deposits, is so remarkable as to deserve especial attention 

 from all those interested in the former inhabitants of our 

 islands. In the first place, the history of its discovery is 

 somewhat curious. Thus,some time previously to i86i,Mr. 

 J. Harrison, of Charmouth, obtained from the Lower Lias 

 of that neighbourhood portions of the hind-limb of a 

 comparatively large Dinosaur, and, later on, a skull, 

 lacking only the extremity of the muzzle. In the year 

 mentioned, these specimens were described by Sir Richard 

 Owen in the publications of the Palseontographical So- 

 ciety, under the name of Scelidosauriis Jiarrisoni ; the 

 portions of the limb being taken as the type of the genus, 

 and the skull referred to a smaller individual of the same 

 species. Stimulated by the extreme interest aroused by 

 the discovery of this skull, Mr. Harrison continued his 

 excavations on the spot where the latter had been ob- 

 tained, and was rewarded by finding the whole of the 

 remainder of the skeleton, with the unfortunate exception 

 of most of the vertebra; of the neck. The skeleton was 

 extracted in several blocks, and these, after careful " de- 

 velopment " of the bones, were fitted together so as to 

 enable the whole skeleton to be exhibited. 



Until the completion of the Natural History Museum 

 at South Kensington, this magnificent skeleton was, how- 

 ever, from want of space, never exhibited to public view ; 

 and it was not until some three years ago that it was 

 properly mounted and placed in its present position, 

 where, in a handsome glass case which permits a view of 

 both sides, it forms one of the chief treasures of the un- 

 rivalled gallery of fossil reptiles in that Museum. The 

 bones being all firmly cemented together by matrix, and 

 also more or less dislocated out of their normal places, it 

 was, however, of course impossible to mount the skeleton 

 in its natural position — which was probably a semi-erect 

 one ; and it is accordingly now placed with the axis of 

 the vertebral column in a horizontal position. As thus 

 mounted, the specimen is about 1 1 feet in length, but the 

 absence of the cervical vertebne renders it impossible to 

 ascertain its true dimensions, the head being now placed 

 much too near to the shoulder-girdle. The skeleton has 

 been somewhat dislocated, and twisted over to the right 

 side, so that the neural arches and spines of the vertebrae 

 of the back and loins are seen on the right, and the 

 under surface of their bodies, or centra, on the left side 

 of the specimen. Both hind-limbs are entire, although 

 the left one is thrust up by the twist, and has become 

 placed near the tail. The haunch-bones (ilia) of the 

 pelvis still nearly retain their normal position ; and on 

 the left side of the specimen we see the lower extremities 

 of the left pubis and ischium lying crossed over the lower 

 ends of the corresponding bones of the right side. A 

 portion of that part of the pubis which lies in advance 

 of the acetabulum is visible ; and the post-acetabular 

 portions of both the pubis and ischium lie in the original 

 parallel position which is so characteristic of this group 

 of Dinosaurs and of the Struthious birds. The left side 

 of the shoulder-girdle is well preserved, and has the 

 humerus and portions of the bones of the fore-arm in 

 their original position ; but the bones of the hands are 

 wanting. The dermal scutes, with which the body and 

 tail were protected, are seen arranged in longitudinal 

 rows, which have, however, been somewhat thrown out 

 from their original position. We would especially call 

 the attention of those who may think it worth their while 

 to visit the Museum, in order to study this unique speci- 

 men, to the marvellous preservation of the hind-limbs, 

 which permits even the smallest bones of the toes to be 



