AND SAUROPTERYGIANS OF THE PURBECK ETC. 43 



favour of its distinctness from /. Dawsoni. This is supplemented 

 by the evidence of the sacral vertebree and ilium. Thus it has been 

 shown that the dorsals associated with the sacrals are similar to 

 those associated with the types of I. hollinc/toniensis, and that the 

 sacrals and ilium are not referable to /. Daiusoni ; and there is 

 accordingly, apart from the apparent association of some of these 

 sacrals with the above-mentioned types, every reason for regarding 

 this form of sacrum and ilium as referable to /. liollingtoniensis. 

 If I am right in this respect there will be equally good evidence as 

 to the distinctness of the Iguanodon to which I have applied the 

 name last mentioned from /. Fittoni, 



The skeleton, Xo. R. 1636, is remarkable for the great relative 

 length and slenderness of its scapula, and the same feature is 

 apparently shown in an imperfect skeleton from the Hollington 

 quarry (B.M. No. 33), which 1 believe to be also referable to 

 /. liollingtoniensis. 



In the characters of the sacrum and femur /. liollingtoniensis 

 approximates to Camptosaurus, although, as I have already observed, 

 the " pendent " character of the inner trochanter is less strongly 

 marked than in the type of the latter. My reason for referring this 

 species to Iguanodon rather than to Camptosaurus is the modifica- 

 tion of the one phalangeal of the pollex into the conical sjjine 

 characteristic of the former ; but the species must be regarded as 

 connecting the typical forms of Iguanodon with the less specialized 

 genus Camptosaurus. 



[Since the above was written, Mr. S. H. Beckles, of Hastings, has 

 been good enough to send to the British Museum part of the skeleton 

 of a small Iguanodon from the Wadhurst Clay of that neighbour- 

 hood, which affords important evidence as to the characters of 

 /. Fittoni. These associated specimens include the right ilium, a 

 pubis, the left femur, and several more or less imperfect vertcbne. 

 The ilium accords in contour with the type of /. Fittoni^ but in its 

 smaller dimensions agrees with the corresponding bone of /. MantelU ; 

 this smaller size may be indicative cither of immaturity or of sexual 

 difference from the type. 



This ilium shows the peculiar outward curvature of the preace- 

 tabular process, which is obscured through fracture in the type; it 

 has the same inflection of the inferior surface of the postacetabular 

 as in the latter ; and also the rounded surface of the bone in the 

 prcacetabular notch. The difference in the contour of this ilium 

 f om that of the figured ilium of/. MantelU (B.M. No. II. 113) is 

 well seen if the two are i)ut side by side and viewed from the ventral 

 aspect, when a diiference similar to that seen between fig. 1 C and I) 

 is observable. In /. MantelU the surface of the bone forming the 

 prcacetabular notch has a sharp edge, while the inner inHcction of 

 the postacetabular process is much less mark(>d, and does not com- 

 mence till much nearer the posterior extremity. Tlie whole bone is 

 also less deep and less curved from above downwards in /. MantvlU. 



The femur of Mr. Beckles's specimen is very important, since it 

 shows that the inner trochanter was of the " crested '' type of 



