42 MR. E. LTDEKKER ON DINOSAURS OF THE WEALDEN 



the '* crested " type *. The position of this inner trochanter is^ 

 indeed, very similar to that obtaining in the larger femur of /. her- 

 nissartensis t ; but in the latter the trochanter is decidedly of the 

 " crested " type. There is accordingly evidence as to the specific 

 distinctness of the form under consideration from the two species 

 mentioned above. With regard to /. Dawsoni, the femur already 

 alluded to (p. 38) as referable to that species is somewhat larger 

 than the present one, and, so far as its imperfect condition admits 

 of comparison, appears to present structural differences, its shaft 

 being much less curved. The two dorsal vertebrse associated with 

 the femur of the present form are much smaller than those of 

 /. Dawsoni. Other collateral evidence will be adduced as to the 

 distinctness of the form under consideration from the latter species ; 

 but in the meantime it may be observed that in its curved shaft 

 and pendent trochanter the femur before us approximates to that of 

 Camptosaurus %, although these features are not so strongly marked 

 as in the latter. 



Turning now to the sacral and caudal vertebrse from the Hollington 

 quarry (No.E. 1632), which are believed to have been associated with 

 the type specimens, it may be observed that the sacrals are character- 

 ized by the absence of anchylosis between their centra, and also by 

 the flattened haemal surfaces of the latter ; in both of which respects 

 they resemble Camptosaurus. JSTow these sacrals are of the same 

 type as those (No. II. 811) which I have previously referred to /. 

 IJawsoni; the latter (which likewise came from the Hollington quarry) 

 being associated with dorsal vertebrae (No. R. 604) of the same form as 

 those of the type skeleton. There is accordingly every probability 

 that these sacral vertebrae are referable to the present form. There 

 is, however, associated with the sacrals (No. R. 811) an imperfect 

 left ilium (No. E. 811 b), which although much broken and flattened 

 affords important evidence. This specimen is represented in fig. 1 E. 

 Its preacetabular portion differs from that of /. Davjsoni by the 

 absence of an inner roof-like extension, and the whole bone is of a 

 much less massive build. Compared with the ilium of /. Fittoni 

 (fig. 1 C), the present one differs by the shallower preacetabular 

 process, the longer interval between the pre- and postacetabular 

 notches, the greater depth of the preacetabular notch, and apparently 

 also by the more forward direction of the pubic process. Precisely 

 similar characters are found in the imperfect right ilium, belonging 

 to another imperfect skeleton collected by Mr. Dawson (No. R. 1636), 

 which I am accordingly disposed to refer to the present form. 



We are now in a position to sum up the evidence of the specific 

 distinctness of the Hollington Ljuanoclon from the other species. 

 The evidence of the femur justifies its separation from /. Mantelli 

 and /. hernissartensis. The same evidence, so far as it goes, is in 



* See Dollo, Bull. Sci. France «t Belg. 1888, pp. 215-224. 



t Dollo, op. cit. p. 216, fig. 1. When suggesting in the work cited that the 

 present specimen might belong to a young individual of /. bernissartensis, my 

 attention had not been directed to the difference in the contour of the inner 

 trochanter. 



X Compare Dollo, op. cit. p. 216, fig. 2. 



