WEALDEN IGTTAIfODONT AND OTHER DINOSAURS. 57 



far, therefore, as the vertebral evidence goes, it tends to show that 

 Cetiosauriis hrevis is much more nearly allied to C. oxoniensis than 

 to Brontosaurus ; and I cannot consider it by any means proved that 

 it even belongs to the same family as Ornitlio'psis, while I shall 

 have to mention a specimen which may indicate its distinctness 

 from Cetiosaurus. The somewhat remarkable fact still, however, 

 remains, that T can find in the Wealden no anterior caudal vertebrae 

 of the type of those of Brontosaurus which I can refer to Orniili- 

 opsis ; but this is counterbalanced by anterior caudals, shown me by 

 Mr. Hulke, of which drawings have been found in association with 

 his Ornithopsis Leedsi (of which more anon), which are of the 

 characteristic Brontosaurus type. 



With regard, then, to Pelorosaurus, all that can be safely stated is 

 that the type humerus approximates to the Brontosaurus- rather than 

 to the Cetiosaurus-tj^Q^ and that such approximation is in favour of 

 its reference to Ornithopsis. I do not, however, think it would be 

 safe to say, at present, that these two genera are certainly the same ; 

 and even if it be eventually shown that they are so, I am inclined 

 to think that this would be an occasion where strict adherence to 

 priority would be a disadvantage rather than otherwise, and that 

 it would be advisable in any case to retain the name Ornithopsis, 



A humerus closely resembling, in general contour, the type 

 specimen of Pelorosaurus, but with a perfectly solid shaft, is the one 

 from the Ximeridge Clay of Dorsetshire figured by Mr. Hulke in 

 vol. XXX. pi. ii. of the Society's ' Journal,' under the name of Cetio- 

 saurus humerocristatus, and now preserved in the British Museum 

 (No. 44635). I find, however, on comparing this bone with the 

 smaller humerus (No. 41626) from this formation, figured by the 

 same writer in vol. xxv. pi. xvi. of the ' Journal,' and subsequently 

 made the type of the genus Ischyrosaurus, Hulke, that the latter, 

 which has lost the side bearing the deltoid ridge *, evidently belongs 

 to a closely allied form, and can only be distinguished from the 

 former by its inferior dimensions. 



Under these circumstances the obvious course would be to refer 

 Cetiosaurus humerocristatus to Ischyrosaurics, were it not for other 

 considerations. In the first place, the name Iscliyrosaurus is pre- 

 occupied by Prof. Cope, and accordingly cannot stand. Secondly, 

 Prof. Seeley has described some Sauropodous remains from the 

 Kimeridge of Ely, which there is a strong presumption for thinking 

 are specifically the same as C. humerocristatus^ under the name of 

 Gigantosaurus megalonyx. If this be so, there would be grounds 

 for adopting the name Gigantosaurus for the form in question ; but 

 as the types of the former have never been figured, the name can 

 only be regarded as a manuscript one. I do not, however, think 

 that it will be necessary to make a new generic name for these huge 

 Kimeridge Dinosaurs, because it appears to me that there is every 

 reason for believing that the larger Dorsetshire humerus, at least, is 

 generically, and very probably also specifically, identical with the 



* Mr. Hulke did not apparently notice this imperfection, and was thus led 

 to refer the two specimens to different genera. 



