Hector.—On the Fossil Reptilia of New Zealand. 341 
dimensions :—Antero-posterior length 2:7 inches, transverse diameter 3:2 inches, 
vertical 2-8 inches, diameter of neural canal :75 inch. 
No. le.—To this same species Dr. Haast has referred a fine specimen, 
which is exhibited in the Canterbury Museum, obtained at Boby's Creek, at 
Waipara. It is only partially worked out from the matrix, but shows the 
ventral aspect of the greater part of the trunk and tail of a Plesiosaur that 
measured probably 10 feet in length, the distance between the anterior 
margin of the thorax and the pubic arch being 4 feet. The portions of the 
skeleton which are visible are thirty-five vertebre belonging to the dorsal and 
caudal regions, the scapula and pelvic arches, with appendages, and both 
vertebral and abdominal ribs. The transverse diameter of the vertebral centra 
_ is 2-15 inches, being greater than the vertical, while the length is only 1-7 inches. 
The height of the neural spines and the length of the transverse processes is 
about equalto the height of the vertebral centrum in the midale part of the 
back. The caudal vertebre diminish rapidly in diameter and length towards 
the extremity of the tail The c@racoids form a very wide, compressed, bony 
plate, not much longer than the width in the middle, but constricted posteriorly, 
their length being equal to about six thoracic vertebre. The ribs are slightly 
compressed, and do not agree well with Professor Owen’s description of the 
type of the species to which this has been referred. The form of the vertebral 
centrum also exhibits so marked a difference in the proportion of the transverse 
diameter to the length, as to lead to the belief that it must have been a very 
different animal; but until it has been more clearly worked out from the 
matrix this cannot be well decided. 
2. PLESIOSAURUS CRASSICOSTATUS, Owen. Geol. Mag., 1870, p. 52. 
No. 2 a.—This fine slab, collected by Mr. К. L. Holmes at Boby’s Creek, 
Waipara, exhibits the left side of the thorax and neck of a well-grown animal. 
A. fullsized drawing of the specimen sent to Professor Owen enabled him to name 
this species ; but, as the bones have since been more completely worked out 
from the matrix, and three dorsal centra discovered and extracted from beneath 
the ribs, I am able to add some further particulars regarding this interesting 
specimen. 
: Professor Owen remarks :—** Whoever may glance at a specimen or figure 
of a similarly-preserved trunk of a Plesiosawrus will appreciate the generic 
character of the ribs in the New Zealand fossil They are robust, subcircular 
in section, expanding somewhat, or thickening, at their middle, obliterating 
there or leaving very little of intercostal space, at least in the collapsed 
condition of the chest. They are likewise solid." 
The portion of the neck which has been preserved consists of seven cervical 
centra, each 1:4 inches in length, with 2:5 inches transverse, and 1:3inches vertical 
