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Description of Plates XXVII.— XXXI. 

 Plate XXVII. 



A. Plesiosaurus australis, Owen. (No. 1 b, one-fifth of natural size). Locality — 

 Amuri Bluff. 



General view of thorax, seen from above, as exposed in the slab, showing the 

 neural spines traversed by a vein of calcspar, which continues through one of the iliac 

 bones and both femora. The large quadrate pubic bones lie on either side. The riba 

 are recurved and continuous with the transverse processes. A few only of the dorsal 

 and caudal vertebral centra preserved in the slab have been figured, and one group of 

 the abdominal ribs in the upper right-hand corner. 



B, C. Polycotylus tenuis, Hector. (No. la, one-fourth natural size.) 

 B, B', humerus ; C, C, anterior dorsal vertebral centrum. 



Plate XXVIII. 



A. Plesiosaurus crassicostatus, Owen. (No. 2a, one-third natural size.) 



Ribs of the right side and ventral aspect of the cervical vertebrae, one of which is 

 displaced so as to exhibit the articular facet. Three centra of dorsal vetebrse, figured in 

 the upper part of the plate, were extracted from beneath the ribs. 



B. Plesiosaurus hoodii, Owen. (No. 3a, one-half natural size.) 

 B, left side ; B', ventral view ; B", anterior view. 



Plate XXIX. 



Mauisaurus haastii, Hector. A. (No. 8a, one-sixth natural size). 



General view of the coracoids and paddle of the left side, restored from the portions 

 collected by Dr. Haast at the Cheviot Hills. The paddle has nearly one-third greater 

 breadth than is shown, being seen obliquely in the drawing. 



a, superior aspect of the humerus ; a', inferior aspect of the same bone, from a cast, 

 placed in the position of the humerus of the right side ; a", side view of the humerus ; 

 b, fragment of the scapula. 



B. (No. 8c, one-third natural size. ) B, posterior ; B', anterior, and B", siiperior 

 view of an anterior dorsal vertebra. Locality — Amuri Bluff. 



Plate XXX. 



Leiodon haumuriensis, Hector. 



A. Jaws, with teeth of right side. (No. 10a, one-fifth of natural size. ) 



The teeth have been made more distinct than in the original, but are copied from 

 the jaw of the other side, in which they are well preserved. The fourth and tenth pairs 

 are broken off and not represented, but the bases are quite distinct in the specimen. In 

 many of the others the enamel has flaked off in working out the bones from the matrix. 

 The specific name is from Haumuri, the correct Maori spelling of the name of the locality 

 whence this fine specimen was obtained. 



B. Posterior dorsal or lumbar vertebra. (From No. 10c?, one-half natural size.) 



B, view of right side ; B', anterior articular sui'face, showing the form of the cup ; 

 C, portion of rib from same slab, showing the excavated form of the articular surface. 



