318 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



" a coracoid of an elongated form, which has a thick neck near 

 the humeral extremity, that enlarges into a plane and wide 

 portion, to attach itself to the sternum. The omoplate or 

 scapula is not unlike the coracoid ; its plane forms a narrow 

 isosceles triangle ; its neck is sub-cylindrical and curved 

 internally, and widens to present a face to the coracoid : on 

 the external edge of this is an articular apophysis, which with 

 the corresponding one of the coracoid, forms the cavity for 

 the reception of the head of the humerus. There are no 

 traces of clavicles ; the coracoid alone appearing to have 

 formed a buttress against the sternum. 



The Scapulae of the Hylseosaurus, (Lign. 69, fig. 1,) cor- 

 respond in many particulars with those 

 of the Crocodiles above described, and 

 unite with the Coracoids in a similar 

 manner. The head of the bone is six 

 inches wide, and very thick ; it is con- 

 tracted at the neck, and passes off into 

 a flat and wide extremity : the articular 

 facet is 2^ inches high, and 3J wide. 

 These bones are about twelve times 

 larger than the scapulae of a crocodile 

 LIGN. 67. 3 feet long ; they are marked 7, 7, in 



CORACOID BONE OF THE iqn. 66. 



HYLJEGSAURUS. JJ_ A* /* a 



(inat.size.) ^ ne Coracoid bones, (Lign. 66, 6, 6, 



and Lign. 67,) are entirely distinct from 

 those of the Crocodile, and are like the coracoids of the true 

 lizards, hatchet-shaped, but not emarginated ; they have no 

 apophyses corresponding with those of the recent Monitors 

 and Iguanas, or the fossil Megalosaurus. 



The longest diameter of the Coracoid is 7 inches; the 

 transverse diameter 5-1 inch : it presents a large articular 

 surface for the glenoid cavity, which is formed mutually by 

 this bone and the scapula. 



Near the neck of the bone there is a foramen for the 

 passage of vessels, as is the case in the lizards, but not in the 

 Plesiosaurus, Ichthyosaurus, 1 Megalosaurus, or Crocodile." 



1 I have seen an exception in a coracoid of an Ichthyosaurus, in which 

 the humeral extremity throws off a kind of apophysis, that unites at the 

 upper end of the glenoid cavity, and produces a foramen. The above 

 account is extracted from my " Geology of the South-East of England." 



