246 H. G. SEELEY ON THE DINOSAURS 



17. On the Dinosaurs from the Maastricht Beds. By H. G. 

 Seeley, Esq., F.R.S., F.G.S., &c, Professor of Geography in 

 King's College, London. (Bead March 7, 1883.) 



In 1871 the Geological Department of the British Museum acquired 

 the celebrated collection formed by Professor van Breda at Haarlem. 

 It was especially rich in the remains of fossil reptiles from Maastricht ; 

 and among the bones of Mosasaurus were arranged five other speci- 

 mens, which Mr. William Davies, F.G.S., soon recognized as Dino- 

 saurian. So far as is at present knowu, these are the most recent 

 evidences of the Dinosaurian order in geological time ; and in view of 

 this fact, I am happy in having the permission of Dr. Henry Woodward, 

 F.R.S., the Keeper of the Department, to offer the Geological Society 

 some account of the structure of the last known survivors of the 

 group. I avail myself the more readily of this permission, since I. 

 do not remember to have seen in any of the continental museums 

 other specimens exhibited which would add materially to the British- 

 Museum evidence or modify my conclusions. 



These five bones belong to two types. One femur is Megalosaurian ; 

 and although it is quite possible that other parts of the skeleton 

 may enable their discoverer to refer the animal to a new genus, I 

 have not felt justified in differentiating the genus from Megalosaurus 

 on the evidence of one bone, imperfect distally, and with the proxi- 

 mal end worn. The other specimens are Iguanodont. I have re- 

 ferred them to an Iguanodont genus Orthomerus ; and I have no 

 doubt that the remainder of the skeleton will eventually show them 

 to belong to a new generic type. For more certain reference, I give 

 the British-Museum numbers on the specimens. 



Megalosaurus Bredai, Seeley. 



No. 42997. This right femur is of Megalosaurian type. 



The bone is very imperfect ; the distal end has been sawn away 

 (fig. 1, a), so that the bone shows no indication of the distal articula- 

 tion, though some changes in the form of the shaft suggest that no 

 large portion is lost (fig. 1,b). The proximal end is a good deal 

 worn and broken away (fig. 1, b) ; but enough remains to demon- 

 strate its more remarkable characters. 



The femur, as a whole, is remarkable for its slender form, its 

 superior bow- shape curvature, the lateral compression of the proximal 

 articulation (fig. 1, b, h), and the extent to which it is directed inward, 

 for the proximal trochanter, which is separated from the proximal 

 end of the bone in front (fig. 1, a, p t), and for the proximal position 

 and small size of the lateral trochanter (fig. 1, b and c, It). 



The fragment, as preserved, is nearly 29 cm. (ll|-in.)long. The 

 shaft of the bone is unusually compressed from side to side, so as to 

 make the vertical thickness (fig. 1, b) as much as or more than the 

 width (fig. 1, a) ; and while the surfaces of the bone generally are 

 rounded, the superior or anterior aspect is marked by a blunt ridge 



