298 A NEW PLESIOSAFE FROM THE WEALD CLAY. [vol. Ixxviii. 



Plate XV. 

 [All figures are a quarter of the iiatui'al size.] 



Fig-. 1. Shoulder-girdle, from above. 



2. The same, from the front. 



3. The same, from the side. 



4. Right humerus, from above. 



5. Two middle ventral ribs. 



\_cl. = clavicle ; co7'. = coracoid ; for. — opening bounded by scapula, coracoid, and 

 clavicle; /.=notch or foramen in coracoid; grZ.=glenoid cavity; h.=^ 

 head of humerus; i.cZ.— interclavicle ; sc. = scapula ; h(..= tuberosity of 

 humerus.] 



Discussioisr. 



Dr. A. Smith Woodwaed referred to the interest of the section 

 at Berwick, which shows the top of the Weald Cla}'' and the base of 

 the Lower Grreensand. The Plesiosaur was found b}^ ]Mr. Tooth in 

 a well-defined layer of septarian nodules in the Weald Clay. The 

 specimen was valuable, as showing the true shape of the clavicles 

 and scapulae : they were isolated in the nodule ; but, when they 

 were extricated and placed in contact, their curved surfaces fitted 

 exactly. The neck was evidently more flexible than in the earlier 

 Plesiosaurs. He agreed with the Author that the new specimen 

 might be regarded as representing an ancient type, which owed its 

 survival to its retreat to life in a river or lake. 



Baron F. Nopcsa pointed out that in most grouj)S of marine 

 reptiles one can distinguish a long-necked and a short-necked 

 series. Among the Lacertilia the short-necked forms are repre- 

 sented by the Aigialosaiu'ia and their descendants the Mosasauria, 

 the long-necked by the Dolichosauria ; of the Ichthyosauria, 

 which are short-necked, the long-necked relatives seem to be the 

 IMesosauria. 



The Peesideistt (Prof. A. C. Sewaed) referred to the close 

 resemblance between the W^ealden plants of Sussex and those found 

 in the Uitenhage Series of the Cape Province, a resemblance that 

 appears to be shoAvn also by the reptilian remains from the two 

 regions. 



The Atjthoe expressed his thanks for the reception accorded 

 to his paper. 



[September 23rd, 1922.] 



