1864.] IN THE MUSEUMS OF HOLLAND AND BELGIUM. 401 
The hands, from the carpus downwards, the pelvic bones, and some 
of the terminal caudal vertebree are wanting, also the lachrymals and 
malars from the skull; in other respects the skeleton is complete. 
Not being yet articulated, the separate bones could be examined 
with great facility. Both epiphyses are ankylosed to the bodies of 
the three first cervical vertebrae; the anterior epiphyses only are 
united on the fourth and fifth. From this as far as the ninth caudal, 
inclusive, they are detached; on the tenth caudal the hinder, and 
on the succeeding ones both epiphyses are firmly united. On the 
humerus the upper epiphysis is partly, and the lower one completely 
united to the shaft, all traces of the original separation of the latter 
having disappeared. The upper epiphyses of the radius and ulna 
are in the same condition ; but those at the lower end are separate. 
The transverse processes of the cervical vertebrae show, from the 
condition of their terminal surfaces, that they are not quite complete. 
The upper edge of the scapula appears completely ossified in the 
middle, but must have been cartilaginous towards the two extremities. 
These conditions taken together show that the animal was in the 
adolescent stage, and had probably attained very nearly its full size. 
The skull is 9! 8" long in a straight line; the vertebra, placed 
close together and without their epiphyses, measured 30!; so that, 
allowing for the epiphyses, intervertebral spaces, and the end of the 
tail, the animal could not have been less than 45 feet long. 
The number of vertebre present is 54; and 3, or probably 4 of 
the caudal are wanting, raising the total number to 57 or 58. Of 
these, 7 are cervical, 14 dorsal, and about 13 or 14 lumbar ; but, the 
articular surfaces for the anterior chevron bones not being well 
marked, I could not be certain where the tail should be considered 
to begin. There are 14 pairs of ribs. 
The skull presents the general characters of the genus Siddaldius. 
The only important difference that I could find between it and the 
specimen last described is in the form of the orbital process of the 
frontal bone, which is narrower at its outer end, approaching more to 
the form characteristic of Physalus, although by no means so narrow 
as in this. The nasals (fig. 5) are long and narrow, nearly flat on 
their upper surface, and slightly shelving downwards from the middle 
line. Their anterior border is rather less produced near the middle 
line than at the sides—the reverse in this respect to the Zuyder Zee 
specimen. The tympanic bones are 4'°6 long, 3!°5 in greatest 
breadth, and 2"-5 thick: their form is seen in the annexed woodcut 
(fig. 16). The lower jaw has a very slight curve and a low coronoid 
process, the highest part of which is 20" from the hinder end of the 
bone. It is triangular in form, rounded at the apex, with a base 
about 4" in breadth, and rising about 24" in height. The principal 
dimensions of the skull, in inches, are given in the following table, 
compared with those of the skulls of the two other specimens of the 
genus mentioned in this notice. 
Proc. Zoo. Soc.—1864, No. XXVI. 
