PECULIAR HORN-LIKE DINOSAURIAN BONE EROM THE WEALDEN. 185 



12. On a PECULIAR Horn-like Dinosaurian Bone from tJie Wealden. 

 By I-i. Lydekker, Esq., B.A., F.Gr.S. (Eead December 4, 

 1889.) 



Among a small series of vertebrate remains lately sent from tbe 

 Dorsetshire County Museum to the British Museum there is an im- 

 perfect bone from the Wealden of Brook, Isle of Wight, so unlike 

 any specimen from those beds which has hitherto come under my 

 observation that I deem it worthy of a brief notice. This specimen, 

 which is represented on a reduced scale in the accompanying wood- 

 cut, is a stout and short cone-like bone, of some 5| inches in 

 length, with the larger basal diameter measuring 4 inches. The 

 cone is somewhat compressed, with a distinct backward curvature, 

 the summit being imperfect. The outer surface is rugged, with 

 irregular longitudinal ridges ; while the base is extensively hollowed, 

 and has a smooth and mamillated surface, recalling that of the 

 cancellous cavities found in the base of the horn-cores of the Bovidse. 

 In all these respects this specimen appears to present a close resem- 

 blance to the horn-cores of the Dinosaurian skull from the Jurassic 



t^...'.'>^;>i<Mia.^^fa^ 



Horn-core (?) of a Dinosaur ; from the Wealden of the Isle of Wight. 

 ^ nat. size. 



of North America, described and figured by Prof. Marsh in the 

 ' Amer. Journ.' ser. 3, vol. xxxvi. pi. xi., under the name of Ceratops, 

 A less marked resemblance is also presented to the longer horn-like 

 bone from the Grcensand of Austria, figured by Prof. Seclcy in vol. 

 xxxvii. pi. xxvii. fig. 4, of the Society's ' Quarterly Journal,' under 

 the name of Cratcnomus, which Prof. Marsh (Gcol. Mag. dec. 3, vol. 

 vi. p. 207) regards as a veritable horn-core. The dermal spines of 

 Bylaiosauriis and Folacanthus do not show a basal structure at all 

 like that of the present specimen ; and it certainly does not belong 

 to Ljuanodon. 



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