414 (hi the Skeleton of a large Plesiosaur. 



It seems prob.able that Plesiosnurus megacephalus^ Stutch- 

 hury. sljoTild also be referred to Rhoinaleosaurus. 



Some ilimensious of this speciiueu (K. 1853) (in milli- 

 raetres) are : — 



Skull : 



Width of premaxillary expansion 167 



„ constriction at maxillo-preinaxillary suture. . . . 133 



Ijeno:th (approx.) from tip of snout to external nares .... 310 



AVidth of articular end of quadrate 127 



Mandible : 



Lencrth of symphysis 1 60 



Width of syniphysial expansion (exaprgorated) 203 



Depth of ramus just behind symphysis 76 



Length. Height. Width. 



Cervical vertebral centra, No. 1 * 56 91 102 



„ „ „ No. 4 66 99 109 



„ „ „ No. 7 63 99 112 



First thoracic centrum 61 115 app. 133 app. 



iSecond „ „ 71 123 131 



Anterior dorsal „ 66 1 15 144 



Middle „ , 79 156 145 



Last lumbar 72 131 132 



Largest caudal with chevrons 64 116 133 app. 



Shoulder-girdle : 



Width in straight line across coracoids at posterior angle 



of glenoid cavity 710 



,, „ at middle of glenoid cavity 660 



Greatest length of coracoid, so far as preserved 560 



Height of glenoid surface of coracoid 127 



Width of each coracoid at narrowest point behind glenoid 



cavity 257 



vScapula : 



Width of coracoidal end of scapula , 170 



,, ascending ramus of scapula 82 



Thickness of ascending ramus of scapula 60 



Humerus: 



Length 710 



Width of head 162 



„ distal end 335 



„ middle of shaft 150 



Pelvis : 



Greatest length of pubis 360 



„ width of pubis 435 



Length of pubic symphysis (approx.) 295 



liength of blade of ischium 372 



Greatest width of ischium 348 



Length of articular end of ischium 194 



♦ These numbers do not denote the actual position in the neck, many 

 vertebrae being missing. 



