458 



PROF. W. J. SOLLAS ON A NEW SPECIES OF PLESIOSATJRTJS 



This anomalous position I altogether fail to explain : if the lapels 

 could be shown to be precoracoids, all would be clear ; but this view 

 is not without difficulties. 



The dimensions of the bone are given below : — 



inches. 



Antero-posterior diameter in the median line 



(fig. 2, op) 3-65 



Maximum antero-posterior diameter (ib. c d) 6-4 



Antero-posterior diameter from a tow 5*25 



Breadth (twice the line IV) 8*6 



Length of wing (g h) 8*4 



Width of anterior excavation (eg) 2*55 



Depth of anterior excavation (ax) 1'05 



Depth of posterior incision 2*1 



The Coracoids. 



The coracoids (fig. 4) have the usual Plesiosaurian form, presenting 

 together a close and almost ludicrous resemblance to the front of a 

 short jacket. 



Pig. 4. — Diagram of the Right Coracoid. (Scale J.) 



The inner margins of the bones meet for half their length in a 

 straight median harmonia, diverging gently outwards from each end 

 of it. The outer margin has a simple concave sweep backwards 

 behind the articulation for the humerus ; the anterior margin pro- 

 jects in an elliptical curve in front, the outer edge of the curve sink- 

 ing into a curve backwards, which joins the almost straight margin 

 of the scapular articulation. The bone is thickest where it furnishes 

 the articulations for the scapula and humerus. Thence it continues 

 with only slightly diminished thickness along a ridge or keel, which 

 extends transversely to its inner margin. This ridge, which rises 

 from the ventral surface of the bone, and as shown by a transverse 



