A NEW DINOSAUR. 
135 
of the pedicle of the arch is preserved, as may be seen in Plate XV. 
Unfortunately the postzygapophysial region and the whole of the platform 
supporting the transverse process are missing. Judging from fragments exposed 
in the matrix over the remnant of the contiguous vertebra, however, the 
region of the diapopbyses was situated high in the neural arch, — at least as 
high above the centrum as the vertical diameter of the centrum. 
Rib. — A fragment of a rib is preserved in the matrix between the two 
vertebrae on the left side (Plate XV.). In section this is oval, with one side 
flattened, the diameters being 90 mm. by 40 mm. 
Neuhal Canal. — The matrix in the site of the neural canal is well 
preserved in all three specimens, and is transversely oval in section. The 
average transverse diameter is 50 mm., and the vertical height is 35 mm. 
The cylinders of matrix are partly exposed above in Specimens B (Plate 
XVII.) and C. 
Immediately above the region of the canal in A is an arch of bone 
showing an elongated isosceles triangle in section, as seen in the matrix, but 
the plates are very thin as preserved. This structure is seen in the anterior 
and posterior sections now exposed in Specimen A, and it is also noticeable 
in the section of Specimen B. It appears to be a distinctive feature of the 
intramural laminae of the neural arch (Plates X\ I. and XVII.). 
Specimen B shows subequal portions of two incomplete vertebrae. The 
anterior element mainly consists of the expanded rim of the “ cup,” which is 
closely adpressed to the “ ball ” of the adjoining unit. The preserved portion 
of the body of the centrum is almost entirely intramural and consists of a mosaic 
of large cancelli. The matrix of part of the neural canal is present. 
The associated vertebral fragment consists of an incomplete centrum 
containing a pleuroecele on each side. On its posterior surface it exhibits the 
inner portion of the deep cup. So much of the rim is missing, however, that 
the maximum length of the complete vertebra cannot be precisely estimated. 
The concavity is now covered with a thin tessellated layer, which evidently 
represents the original cartilage now changed to crystals of carbonate of lime 
(Plate XVII.). The preserved portion is 180 mm. in transverse diameter, 
with a vertical height of 135 mm. 
The anterior base only of the neural arch is preserved. As exposed in 
the matrix, the right and left anterior laminae exhibit “ saddle-shaped ” contours 
resembling those described from the more complete elements in specimen A. 
The neural canal matrix, consisting of a vertically compressed oval cylinder 
(54 mm. x 40 mm. in section) is also preserved. Above this an elongated 
isosceles triangle of matrix is enclosed within thin plates of bone, as in 
Specimen A. 
The pleurocoeles in this centrum are less elongated than those in 
Specimen A, and are infundibulate. They are more obliquely placed in the 
