'tis The Rev. \V. D. Conybeare on the Discovery 



inquiry that there were two species, we learn from the speci- 

 mens already procured that the specific distinctions were very 

 slight, that noticed in the coracoids being in fact the only one 

 that I have been able to detect after a careful collation of the 

 most important parts in all the speciniens that I have exa- 

 mined. 



The scapula has been correctly represented in my first me- 

 moir; but the humerus, which I had there figured from the 

 only specimen in which I had seen those two parts together (and 

 which, having belonged to the late Mr. Catcott, is preserved 

 in the public library at Bristol), in consequence of an accidental 

 dislocation is exhibited in an inverted position. The clavi- 

 cles consist of two transverse and one central piece. The for- 

 mer are the clavicles, strictly speaking; the latter may, per- 

 haps, more properly be referred to the steinum. The cor- 

 responding part or furculai- in the Ichthyosaurus also consists 

 of two transverse and one central piece, as does that of the 

 OrjiitJiorynchus, when young, as has been noticed by Mr. Clift ; 

 but the central piece in these animals forms merely a short 

 stem or handle (as it may be called) connected with the trans- 

 verse clavicles, whereas in the Plesiosaurus it is considerably 

 more developed. The general analogies between these parts 

 in the reptile tribe, in the Oniithotynchiis, and in birds, have 

 been ably pointed out by Geoffroy St. Hilaire and Cuvier. 



In the plate containing a restoration of the Plesiosatmis, 

 (Plate 1 1 1.) I have added, for the purposeof comparison, a sketch 

 of this part in the Ichthyosaurus. That published in the Philo- 

 sophical Transactions does not exhibit the tripartite division 

 of the furcula, and erroneously makes its branches curve con- 

 siderably too much upwards. The present outline is founded 

 on three very perfect specimens, which entirely agree with one 

 another in the parts here represented, and leave no doubt of 

 their actual form. 



Extremities. — The humerus articulates immediately with the 

 bones, which in my preceding descriptions I had considered 

 as the first row of the carpus ; which contains only two in- 

 stead of the three pieces placed together in the conjectural re- 

 storation. I have again to acknowledge the error into which 

 I have been led in the insertion of a supposed radius and ulna 

 between these parts; for the two pieces which form the first 

 row formerly ascribed to the carpus, now appear to be the true 

 representatives of the radius and ulna, though greatly differuig 

 in form from the usual type of those parts. 



The conjectural restoration of the paddles would very nearly 

 apply to the posterior paddles as exhibited in this specimen, 

 by abstracting the outer bone from this supposed carpus, and 



removing 



