Description of Plates XXVII.—XXXI.
Plesiosaurus australis, Owen. (No. 1b, 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 ribs 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. 7a, one-fourth natural size.)
B, B′, humerus; C, C′, anterior dorsal vertebral centrum.
A. Plesiosaurus crassicostatus, Owen. (No. 2a, one-third natural size.)
Ribs of the right side and ventral aspect of the cervical vertebræ, one of which is displaced so as to exhibit the articular facet. Three centra of dorsal vetebræ, 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.
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″, superior view of an anterior dorsal vertebra. Locality—Amuri Bluff.
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. 10d, one-half natural size.)
B, view of right side; B′, anterior articular surface, showing the form of the cup; C, portion of rib from same slab, showing the excavated form of the articular surface.
Taniwhasaurus oweni, Hector.
A, B. Portion of head and lower jaw. (No. 11c, one-fourth natural size.)
A, upper surface of cranium; A′, side view of the same; B, fragment of the lower jaw, seen from above, and restored to its proper position relative to the cranial fragment; B′, lower jaw seen from the right side. These bones are much broken, and the drawing of the lower jaw is to some extent a restoration.
C. Paddle bones. (No. 11b, one-fourth natural size.)
A vein of calcspar, which is shown in the drawing, passes through the ulna and across the articulations with the humerus above and the carpal below. In the slab the radius has been displaced from its proper position, but has been restored in the drawing, and fits exactly with the other bones into its position. On the same slab, but not connected with paddle bones, are fragments of ribs and of a smooth, radially-striated pelvic (?) bone, not represented on the plate.