of an almost perfect Skdelon cf the Plesiosaunis. 417 



to have been connected with the extremities of" the ribs by 

 cartilages : the nice adaptation of tliese parts is beautifully 

 displayed in the specimen. 



The pelvis is finely displayed, and resembles the usual type 

 of this part in reptiles, of which the turtle perhaps affords the 

 best example for comparison with the fossil : the ilium is re- 

 duced to a long and slender bone, which might, if seen de- 

 tached, be mistaken for the os pubis ; that of several species of 

 turtle is exactly similar. The ischium is like that of most 

 reptiles ; and the pubis, as is also common in this class, is so 

 greatly dilated as to be liable to be mistaken for the ilium 

 if found separately. All these parts are very nearly in situ, 

 and the manner in which they unite to form the acetabular 

 socket is easily perceived ; the oval forniation between the 

 ischium and pubis is also quite distinct. 



Humero-sternal parts. — In one of the specimens of Saurian 

 remains, presented by Colonel Birch to the Museum at Ox- 

 ford, the humero-sternal, or nxihuY humero-clavicular, parts on 

 one side of the animal are almost perfect. It is only at the 

 extremities of the clavicle and scapula that the bones them- 

 selves are preserved ; but the intermediate parts, though re- 

 moved, have left an impression of their lower surface. Enough 

 remains to enable us with certainty to identify these bones 

 with more perfect specimens of the same, which have been 

 found in a detached state. It is from these materials that I 

 have effected the restoration of the humero-clavicular parts 

 represented in Plate III. fig. 2. 



The humero-clavicular parts consist, as in birds, and as in 

 the lizard and some other reptiles, 1st, of coracoid bones se- 

 parated from the scapula ; 2d, of a small scapula ; and 3d, of 

 clavicles. 



The coracoid bones in the specimen at Oxford are greatly 

 elongated, in comparison of those represented in my first me- 

 moir, though resembling the latter in every other particular. 

 I hesitate to consider this diflterence as specific, because the 

 shorter coracoids evidently belonged to a much younger in- 

 dividual than the longer, as appears from the circumstance of 

 these and other bones, which have become anchylosed in the 

 latter case, remaining distinct in the former. I ought, how- 

 ever, to add, that a third fragment of this part, which certainly 

 belonged to a large adult, and exhibits the anterior })orti<>u 

 of the two coracoids adhering to a series of anterior dorsal ver- 

 tebra', agrees in form jnost nearly with the shorter speci- 

 men. The specimen belonging to the duke of Buckingham 

 possessed the long coracoids, traces of ihem beiM!>' very evi- 

 dent beneath all the anterior ribs. Should it appear on further 



Vol. C5. No. Ii2G. June 1825. ^ O inquiry 



