O. C. Marsh— Restoration of Brontosaurus. 83 
place, they are attached to the occiput just above the foramen 
magnum, and extend backward and outward, overlapping the 
lateral pieces of the atlas, thus protecting the spinal cord at 
this point, which would otherwise be much exposed. 
These bones are short, flattened, and slightly curved, resem- 
bling somewhat a’ riblet. e anterior end is thickened and 
rugose for attachment to a roughened surface on the exoccipital, 
just above and outside the foramen magnum. The shaft is 
flattened from above downward, and gradually converges to a 
thin posterior end. In Morosaurus grandis, these bones are about 
65 mm. in length, and 30 along the surface which joins the occi- 
put. They correspond in position to the muscle in mammals 
known as the rectus capitis posticus minor. 
_ in the existing Cormorants (@raculus) a single slender bone 
IS articulated to the occiput on the median line. is, 
10wever, does not correspond to the bones here described. 
To distinguish it from the post-occipitals, it may be called 
the nuchal bone. 
STAPES WANTING, 
In the skull of Morosaurus in which the post-occipital bones 
were found in position and the other bones at the base of the 
skull were undisturbed, a careful search was made for the 
stapes, but no indication of it was found. Its absence in this 
Specimen, so well preserved, would indicate that it was wanting 
in this genus, if not in the other Sauropoda. 
CoLUMELLA PRESENT. 
Hyor BONES. 
There are two pairs of hyoid bones in the Sauropoda. They 
are elongated, souks: and somewhat curved. In Lrontosaurus 
excelsus, they are 210 and 130 mm. in length respectively. 
tened arched processes, which meet with the squamosals 
at their outer ends. There is no parietal foramen. The 
Squamosals lie upon the par-occipital processes. They have a 
