1905.] dilVosaur cetiosaurus leedsi. 241 



in the fossil at the upper border. The bone becomes thick and 

 massive in the lower part of the proximal end, whei-e it forms half 

 the ai-ticular socket for the humei-us ; above this it expands into 

 a thin lamina of unknown but probably small extent. The 

 coi-acoid seems to have been neai-ly quadrangular and somewhat 

 broader than long, though its upper edge is incomplete in the 

 fossil. Its thin uppei' half is anchylosed with the proximal 

 expansion of the scapula ; but its massive lower half, which 

 enters into the articular socket for the humerus, is separated 

 from the scapula by a cleft, which must have been originally filled 

 with cartilage. The bone is pierced with the usual oblique oval 

 foramen near the middle of the border which articulates with the 

 scapula. 



The humerus (text-fig. 47, p. 240) is complete in the fossil and 

 scai'cely crushed; but an opportune transverse fracture permits the 

 obsei-vation that the shaft has a small cavity, perhaps an original 

 medullary cavity, perhaps due to decay (text-fig. 47 A). As seen 

 from the front, the bone is short and stout, with the thickened 

 articular head near the inner end of its expanded proximal border. 

 The deltoid crest (cl.) is thick and prominent, not extending below 

 the upper half of the shaft. The distal end of the bone is deeply 

 furrowed for a cap of cartilage, and its large inner condyle bulges 

 downwards. The ulna and radius (text-fig. 48, u., r., p. 240) ai-e 

 imperfect and much broken distally ; but there is not much doubt 

 about the accuracy of their length stated in the table on p. 243, 

 and the shape of their upper articular end is clearly as shown in 

 text-fig. 48. The manus is unknown. 



Hind Limb. 



As shown by the table of measurements on p. 243, the hind limb 

 is considerably longer than the fore limb, the ratio being about 

 3 to 2. The ilium is fragmentary on both sides of the fossil, but 

 the one bone fortunately supplements the other, and justifies the 

 complete outline given in text-fig. 39, p. 233. This element is note- 

 worthy for its great anteroqoosterior extent and the length of the 

 slender pedicle which supports the jDubis. The upjoer rim of the 

 large peiforated acetabulum is not very prominent. The pubis and 

 ischium of another specimen (Brit. Mus. no. R. 1988) have already 

 been described by Prof. Seeley, and have been added in outline to 

 text-fig. 39. The femur (text-fig. 49, p. 242) is complete from end 

 to end, but part of the sui-face of the shaft has decayed and been 

 restored with plaster. It is a i-emai-kably slender bone for so massive 

 an animal, and in broken sections there is no trace of a small 

 medullary cavity. The head of the bone (A.) is relatively large 

 and curved inwards, and it rises above the level of the gieat 

 trochanter (g.t.). The shaft is antero-posteriorly compressed, but 

 bulges considerably backwaitls just above its lower half into a 

 prominent fourth trochanter (t.) on the inner border. The distal 

 condyles are about equal and well separated by a groove. The 

 tibia and fibula are too fragmentary for desciiption, and the 



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