Mi*. J. Vv r . Hulke on a very large Saurian Limb-bone. 155 



up occasionally, but to run habitually upon the ground on its hind 

 legs, its fore paws not touching the earth, which upright carriage 

 necessitates special modifications of the sacrum and pelvic bones. 



The Solenhofen Limestone, in which Pterosauria are frequent, 

 and which has yielded the remains of Archcwpteryx and of Com- 

 psognailius, has also furnished a slab bearing a bipedal track, re- 

 sembling what might be produced by Chlamydosaurus or Compso- 

 f/nathus. It shows a median track formed by the tail in being drawn 

 along the ground ; on each side of this the hind feet with outspread 

 toes leave their mark, while the fore feet just touch the ground, 

 leaving dot-like impressions nearer the median line. Hence the 

 author thought that, while some of the bipedal tracks which are met 

 with from the Trias upwards may be the " spoor " of struthious 

 birds, most of them are due to the bipedal progression of the 

 Secondary Reptiles. 



3. " IS'ote on the Astragalus of Iguanodon Mantelli." By J". W. 

 Hulke, Esq., E.E.S., F.G.S. 



The author exhibited and described an astragalus of Iguanodon 

 from the collection of E. P. Wilkins, Esq., F.G.S. The bone was 

 believed to be previously unknown. It is a bone of iregular form, 

 having on its lower surface the characteristic pulley-shape of a 

 movable hinge-joint. The upper surface presents a form exactly 

 adapted to that of the distal end of the tibia ; so that the applied 

 surfaces of the astragalus and tibia must have interlocked in such a 

 manner as to have precluded all motion between them. The author 

 remarked upon the interest attaching to this fact in connexion with 

 the question of the relationship between the Dinosauria and Birds. 



4. " Note on a very large Saurian Limb-bone, adapted for progres- 

 sion upon land, from the Kimmeridge Clay of Weymouth, Dorset." 

 By J. Yv r . Hulke, Esq., F.R.S., F.G.S. 



The bone described by the author presents a closer resemblance 

 to the Crocodilian type of humerus than to any other bone ; and he 

 regarded it as the left humerus of the animal to which it belonged. 

 Its present length is 54 inches'; but when perfect it could hardly 

 have been less than 63 inches in length. The middle of the shaft 

 is cylindroid. Its transverse section is of a sub trigonal figure, and 

 presents a large coarsely cancellated core, enclosed in a compact 

 cortical ring. The bone is considerably expanded towards the two 

 extremities ; the distal articular surface is oblong, and divided into 

 a pair of condyles by a very shallow vertical groove ; below, the 

 anterior border, in its proximal half, is much wider than the cor- 

 responding portion of the posterior border, and is flattened and pro- 

 duced downwards into a ventrally projecting crest ; and the distal half 

 of this border forms a thin, rough crest, projecting forwards. The 

 presence of these crests distinguishes the present humerus from 

 those of Pelorosaurus and of Ceteosaurus od'oniensis ; but the general 

 correspondence of the bone with the humerus of the latter species 

 leads the author to refer it provisionally to a species of Ccttosaurus, 

 which he proposes to name 0. humero-eristatns. 



