40 MK. E. LTDEKKEK ON DINOSATJKS OF THE WEALDEN 



small dimensions. So far, however, as I can judge from the figure 

 given by Prof. Marsh *, the ilium of the present form appears to 

 present a considerable resemblance to that of the type species of 

 Camj^dosaurus. This is especially shown in the great vertical dej)th, 

 in the form of the postacetabular portion, in the detiection of 

 the pubic process, and the shallowness of the preacetabular notch. 

 The preacetabular process is also of great depth in both, although it 

 is much shorter in the American form. I am not, however, dis- 

 posed to attach much importance to the latter difference, more 

 especially since there is a comparatively long preacetabular process 

 in the ilium of the so-called Ic/uanodon FresiiuicJii, which I am 

 unable to separate from Camptosaurus. In the compressed sacral 

 vertebrse /. Fittoni differs, however, very widely from Cam2:)tosaurus ; 

 and I am accordingly disposed to consider this species as one which 

 while retaining an ilium approximating to that of the less specialized 

 Camptosaurus type, has acquired the sacrum of a typical Iguanodon. 



Iguanodon hollingtoniensis f. — Of this form there is unfortunately 

 no complete example of the ilium among the specimens collected by 

 Mr. Dawson, so that its diagnosis cannot at present be given so con- 

 cisely as is desirable. The specimens which I take as the type of 

 this species are a large number of associated bones from the Wad- 

 hurst Clay of the HoUington quarry near Hastings, one moiety of 

 which (B.M. No. E. 1148) was obtained in 1887, while the others 

 (B.M. No. E. 1629) were collected in 1889. The former moiety 

 comprises the right femur (fig. 2), part of the tibia of the same side, 

 a metatarsal, and two imperfect dorsal vertebrae ; and these speci- 

 mens were provisionally entered on p. 217 of part i, of the writer's 

 ' Catalogue of Possil Reptilia and Amphibia in the British JMuseum ' 

 under the heading of /. hernissartensis, it being suggested that 

 they might belong to an immature individual of that species, although 

 it was also pointed out that they might perhaps be referable to 

 /. Dau'soni. The second moiety includes the two scapulae, the lelt 

 radius and ulna, a phalangeal spine of the pollex, the left femur, 

 parts of the left tibia and fibula, a metatarsal, &c. It is further 

 believed that an associated series of sacral and caudal vertebrae 

 (B.M. No. E. 1632) from the same quarry are referable to the 

 same individual. 



The right femur of the tj-pe skeleton is represented in woodcut 

 fig. 2, and, with the exception of the lesser trochanter and part of 

 the adjacent region, is practically entire, although it has been much 

 crushed and broken. It has a length of some 32 inches (or ap- 

 proximately the same as the corresponding bone of Iguanodon 

 Mantelli), and is characterized by the marked convexity of the 

 anterior profile of the shaft, by the " pendent " form of the large inner 

 trochanter, which is situated in the lower half of the shaft, and by 

 the obliquity of the setting-on of the head to the shaft. Now both 

 the form and the position of the inner trochanter distinguish this 

 bone from the femur- of /. ManUlli, in which this trochanter is of 



* Amer. Journ. ser. 3, vol. xviii. pi. iii. (1879). 

 t Geol. Mag. decade 3, vol. vi. p. 355 (1889). 



