EUROPEAN REPRESENTATIVES. 13 



possible relationships with the Ceratopsia. Among these may be mentioned, as of special 

 interest, (1) the peculiar horn-like dinosaurian bone from the Wealden of the Isle of Wight, 

 described and figured by Richard Lydekker;" (2) a fragmentary bone, also from the Wealden 

 of the Isle of Wight, figured and described by J. E. Lee 6 as pertaining to Polacanthus, and 

 reprinted in his "Note Book of a Geologist;" (3) the various spines and dermal ossicles that 

 have at different times been figured and described by various authors, usually as pertaining 

 to Hylseosaurus, also from the Wealden. c Of these, the last all seem without doubt to pertain 

 to Hylseosaurus or other allied genera, the affinities of which are with the Stegosauridse rather 

 than the Agathaumidfe. The same may be remarked, though with somewhat less emphasis, 

 of the element described by Lee, but from the description and figure of the bone referred to 

 by Lydekker it would appear at first glance that that element might very likely have pertained 

 to a member of the Ceratopsia. From an examination of a cast of the specimen kindly sent 

 me by Dr. A. S. Woodward, of the British Museum, I am convinced, however, that the original 

 represented an ungual phalanx from the first or second digit of a large sauropod dinosaur, in 

 which the proximal end with its articular surface had weathered away in such manner that 

 the softer and more cancellous inner portion, by decaying more rapidly than the denser external 

 wall, produced a cavity slightly resembling that found at the bases of the frontal horn cores 

 in the Ceratopsia. The homologies of these various elements and the position which the different 

 genera to which they have been assigned occupy in relation to the Ceratopsia will be more 

 fully discussed in that portion of this volume relating to the revision of the genera and species. 



a Quart. Jour. Geol. Soc. London, 1890, pp. 185-136. 

 ~t> Ann. and Mag. Nat. Hist., 1843, p. 5. 

 c See Owen, Foss. Rept. Wealden Form., pt. 4, Tables IV and IX. 



