OE THE MAASTRICHT BEDS. 251 



The extreme length of the lateral trochanter is 10^ cm. (4^ in.) ; it 

 is directed backward only. It is narrow, being compressed from side 

 to side, and is most elevated in the middle, while in the larger 

 specimen the greatest elevation is below the middle. One muscular 

 attachment extends along the whole of its inner border, tapering 

 above and below ; while proximally there is a vertically ovate im- 

 pression, nearly 5 cm. (2 in.) long, which runs side by side with the 

 proximal part of this impression. 



The sides of the shaft are remarkably parallel, flattened behind 

 and on the external surface, rounded in front and on the internal 

 surface, though the convexity decreases distally. 



On the external surface is a longitudinal median muscular scar 

 about 5 cm. (2 in.) long ; it is rugose in the middle, and extends to 

 within about 11^- cm. (4^ in.) of the distal end. 



The outline of the distal end is like the letter H, owing to the way 

 in which the anterior and posterior channels between the condyles 

 cut into the bone (fig. 2, d). The inner condyle, as usual, is much 

 the larger posteriorly (fig. 2, d, p), measuring 9 cm. (3f in.) from 

 front to back, while the outer condyle is only 8 cm. (81 in.) from 

 front to back, and it is much more compressed from side to side, 

 especially proximally. 



The transverse measurement over the condyles is 7^- cm. (3 in.). 

 Anteriorly the condyles are deeply channelled by a nearly circular 

 canal (fig. 2, r>, a) which descends obliquely downwards and back- 

 ward and expands on the distal surface, so as to be broader than 

 the posterior channel. 



The extreme width of the proximal expansion of the bone on the 

 external surface, as preserved at the base of the trochanter, is under 

 9 cm. (Sj- in.). The trochanteric process is subtriangular ; it is broken 

 away, but its base is defined by a narrow groove extending backward. 

 The proximal articular end is entirely broken away, though slight 

 traces of its deep median concavity remain on the posterior border. 



On the external lateral aspect is a large rough surface, which is 

 an ill-defined very shallow muscular attachment. It is about 9 cm. 

 (3-^ in.) long, nearly as broad as the lateral surface, is more distal in posi- 

 tion than the lateral trochanter on the opposite inner side of the bone, 

 and extends to within about 17 cm. (6^ in.) of the distal articular 

 surface. 



In the main characters this form of femur closely resembles Igua- 

 nodon ; in nearly all points in which it differs, it approximates to 

 Hadrosaurus. 



No. 42954. Left Tibia (fig. 3). This is a long slender bone, which 

 exhibits the distinctive characteristics of the tibia, although the arti- 

 cular surfaces are gone from both ends, and the cnemial crest is entirely 

 sawn away (fig. 3, a), so as to give the specimen somewhat the aspect 

 of a slender humerus. The bone, as preserved, is 27 cm. (104 in.) long. 

 The proximal end is at right angles to the distal end (fig. 3 c). On 

 the whole the specimen shows the nearest resemblance to Ignanod 'on, 

 but is much more slender, and shows some difference in form. 



The distal end (fig. 3, d), as preserved, is under 9 cm. (34 in.) wide ; 

 Q.J.G.S. No. 154. t 



