Ma)icJicstcr Memoirs, Vol. Iv. ( 1 9 1 1 ), ^V^;. 11. 5 



3rcl. A curious post-axial bone articulating with the 

 humerus and the ulna. This corresponds with a bone 

 figured by Owen in Piesiosaurus riigosiis and by Andrews 

 in Tricleidus. 



The proximal row of the cari)us is composed of four 

 bones, preaxially, the radiale, a small pentagonal bone 

 with facets for the radius, intermedium and carpalia 

 2 and 1.'"' 



The intermedium is a hexagonal bone articulating 

 with the radius and ulna, ulnare, carpalia 3 and 2, and the 

 radiale. 



The ulnare is also hexagonal, articulating with the 

 ulna, pisiform, a small free space, the 5th metacarpal, by a 

 small facet with the 3rd carpale, and with the inter- 

 medium. 



The pisiform is a small pentagonal bone articulating 

 with the ulna and the ulnare, and having three free faces 

 which face proximally, postaxially and distall}' ; the first 

 and last are pitted for cartilaginous extensions. 



The distal row of the carpus consists of the usual 

 three bones. 



This limb is remarkable for the very close and accu- 

 rate fit of the bones composing it ; they are all polygonal 

 and not mere nodules as are the carpals of Plcsiosaunis 

 sensu strictu. 



The post-axial bone lying between the humerus and 

 the ulnare is curious, but is probably of no morphological 

 importance. It maybe due to the " sui)ra-abundant bone- 

 producing power " shewn by the very fully ossified carpus. 



The hind limb is not sufficiently well exposed to be 

 described : it appears to greatly resemble the fore limb, 



* Tlie numbers applied lo the Ciupalia are tluoughoul of purely de.scri[3- 

 tive sisinilicance. 



