364 BRITISH POSSIL REPTILES. 



portion of the skeleton the right coracoid is shghtly bent out of place and thrust under 

 the left one ; and there is no trace of a sternal or entosternal bone in their interspace. 

 The median margin of the coracoid describes an uninterrupted and full convex curve 

 commencing at the angle dividing it from the scapular articular surface ; but it is 

 separated by a concavity or eniargination from the articular surface for the humerus. 

 It is perforated by a moderate-sized elliptical canal, about two inches from the 

 humeral articulation, and in this respect resembles the same bone in the Iguana, 

 Monitors, and Lizards, and differs from that in the Scinks and Chameleons. The 

 antero-posterior extent of the coracoid in the connected portion of the skeleton, PI. 35, 

 is 8 inches ; its transverse diameter 5 inches. 



Tibia of the HylcBOsaurus. PI. 38. 



One of the long bones of a limb, with a phalangeal bone, and a scapula, of the 

 Hylseosaurus, were discovered in a quarry of Wealden stone at Bolney, in Sussex. 



The long-bone is figured by Dr. Mantell as a humerus.* It bears a much closer 

 resemblance to the tibia of the Megalosaurus,! but it is shorter and more expanded at 

 its distal end in proportion to its length. 



The proximal end (PI. 38, fig. 3), which is 65 inches by 3| inches in its long and 

 short diameters, shows a median tuberosity («), divided by a depression from a second 

 smaller tuberosity (4) (this has been crushed in the specimen), which have articulated 

 with the condyles of the femur. Anterior and external to these the proximal end of 

 the bone is produced into a strong " procnemial " ridge ( c ), the front surface of which 

 js roughened for the insertion of a strong ligament. The shaft of the bone rapidly 

 contracts to a trihedral form, with the angles rounded off ; then as rapidly expands, 

 and becomes, as it were, flattened out ; more especially by the production of the outer 

 border (/), which shows a broad and shallow articular depression for the distal end 

 of the fibula. The distal articular surface for the tarsus presents the same form of an 

 oblique, wide, and shallow notch ( e ), as in the Megalosaurus. 



The largest diameter of this end of the bone is 7 inches ; the circumference of the 

 middle of the shaft is 7 inches. At the back part of the shaft, five inches from the 

 proximal end, is the orifice of a canal for the medullary artery, which passes obliquely 

 downwards. The entire length of the bone is 16 inches. 



Metapoditim of the Hyleeosaurus. PL 42. 



The specimen, No. 25.56, in the British Museum, figured in PI. 42, exhibits three 

 metacarpal or metatarsal bones of the same foot, cemented, as naturally connected, by 



* 'Philosophical Transactions,' part ii, 1841. t P- 346, PI. 31. 



